The halls rose in a pyramid, becoming even more beautiful as one mounted toward the apex, and representing more beautiful worlds. Finally they reached the highest one which completed the pyramid, and which was the most beautiful of all:...for the pyramid had an apex, but no base; it went on increasing to infinity. That is...because amongst an endless number of possible worlds there is the best of all, else G.o.d would not have determined to create any.

The world at the apex, the best of all possible worlds, it turns out, is the actual world, the one in which we live.

The vision is unmistakably baroque. It is possibly an apt representation of what it feels like to get lost at Versailles, and perhaps it is best read with music of the period in the back of one's mind. (Handel, incidentally, was Leibniz's fellow courtier at Hanover in the year that the Theodicy Theodicy was published.) The pa.s.sage also oozes the optimism that would later induce Voltaire to satirize Leibniz in the figure of Dr. Pangloss. After all, many would have guessed that our world is one or two levels down from the top of the pyramid, at the very least. was published.) The pa.s.sage also oozes the optimism that would later induce Voltaire to satirize Leibniz in the figure of Dr. Pangloss. After all, many would have guessed that our world is one or two levels down from the top of the pyramid, at the very least.

In any case, the crucial and novel feature in Leibniz's account is his characterization of G.o.d's choice in terms of possible worlds worlds-as opposed to possible things things. According to Leibniz, G.o.d chooses not between, say, allowing Adam to eat the apple or not, but between possible worlds that do or do not include an Adam eating an apple. This marks what Leibniz believed was one of his decisive breakthroughs in the ten years after his journey to The Hague. In his earlier writings, Leibniz's unswerving commitment to the principle of sufficient reason made it difficult for him to conceive of possible things things. For, inasmuch as everything happens for a reason, there are no isolated accidents or random events in Leibniz's world-everything is part of a single, causal tapestry. "Because of the interconnection of things," he acknowledges at the time of his Discourse Discourse, "the universe with all its parts would be wholly different from the commencement if the least thing in it happened otherwise than it had." By raising G.o.d's choice to the level of possible worlds worlds, however, Leibniz can have his principle of sufficient reason and eat it, too, in a sense: that is, he can grant that all things within our world are linked together in a necessary way while still maintaining that the world as a whole does not necessarily have to be the way that it is. "The reasons for the world," he says, "lie in something extramundane."

The concept of possible worlds, according to Leibniz's way of thinking, also neatly solves the problem of G.o.d's goodness. Inasmuch as G.o.d does not choose particular things, he does not choose things that are evil; rather, he chooses a world that, for some reason, must have evil in it. The reason for this world is the principle of the best, which G.o.d applies with perfect precision; and if this world seems to us to have things that deserve the name of evil, we may nonetheless rest a.s.sured that G.o.d could not have made a better choice.

In order to solidify the conclusion that G.o.d must make a choice, Leibniz labors hard to establish a distinction between "moral" necessity and "metaphysical" necessity. G.o.d's decision to create the best of all possible worlds, he grants, exhibits a kind of moral necessity. That is, if G.o.d wishes to be good, he must apply the principle of the best in his choice of possible worlds. But G.o.d's choice does not involve any metaphysical necessity. That is, G.o.d is theoretically capable of ordering up a less than ideal world, or no world at all, should he be so inclined.

At this point, the contrast with Spinoza's concept of G.o.d could hardly be starker-and that is precisely the point behind the vision. The difference goes back to that simple-sounding question: Does G.o.d have a choice? Spinoza says no; Leibniz says yes. Spinoza says that G.o.d has only one world to choose from, namely, the one that follows ineluctably from its own Nature. Leibniz counters that G.o.d always has the option not to create the world; and, when G.o.d decides to go ahead with the project, he faces a choice among an infinite number of possible worlds. Spinoza's G.o.d has no need for anthropomorphic enc.u.mbrances such as a will or intellect, for it has no choices to contemplate and no resolutions to affirm. Leibniz's G.o.d, on the other hand, looks much more like you or me: he must have a capacity for thought and action in order to make his choices. Finally, whereas Spinoza's Substance is well beyond the merely human categories of good and evil, Leibniz's G.o.d is the ultimate do-gooder, as he shuffles through all possible worlds hoping to locate "the best."

In sum, Spinoza believes in an "immanent" G.o.d; Leibniz argues for a "transcendent" one. Spinoza's G.o.d is the immanent cause of things: it creates the world in the same way that an essence creates its properties-that is, in the same way that the nature of a circle makes it round. It is in in the world (just as the world is in it) and therefore cannot conceivably be a.s.sociated with any other world or with no world at all. A transcendent G.o.d, on the other hand, is the "transitive" cause of things. He creates the world in the same way that a watchmaker makes a watch. He stands outside the world, and he would still be G.o.d whether he opted to create this world, another world, or no world at all. He has a certain degree of personhood (which is why we tend to call him "he," in deference to the tradition). Leibniz sometimes uses the phrase "supra-mundane intelligence" to describe his transcendent G.o.d. Dropping the polysyllables, we could also say simply that Spinoza's divinity is one that inhabits the "here and now," while Leibniz's resides in the "before and beyond." the world (just as the world is in it) and therefore cannot conceivably be a.s.sociated with any other world or with no world at all. A transcendent G.o.d, on the other hand, is the "transitive" cause of things. He creates the world in the same way that a watchmaker makes a watch. He stands outside the world, and he would still be G.o.d whether he opted to create this world, another world, or no world at all. He has a certain degree of personhood (which is why we tend to call him "he," in deference to the tradition). Leibniz sometimes uses the phrase "supra-mundane intelligence" to describe his transcendent G.o.d. Dropping the polysyllables, we could also say simply that Spinoza's divinity is one that inhabits the "here and now," while Leibniz's resides in the "before and beyond."

The confrontation between Leibnizian and Spinozistic conceptions of divinity, incidentally, continues to characterize discussions to the present, notably in the field of cosmology (never mind the relatively changeless field of theology). Among contemporary physicists, for example, there are those who maintain that the laws of nature are inherently arbitrary. According to their rather Leibnizian view, G.o.d (or perhaps a Great Designer) selects from among an infinite range of parameters for the laws of nature, and everything else in the world then unfolds within the chosen regime. Others physicists, however, maintain that the parameters that define the laws of physics may ultimately be determined by the laws themselves, such that nature may account for itself in an utterly self-sufficient way. Such theorists may be said to lean to the side of Spinoza.

In the seventeenth century, of course, the difference between Leibnizian and Spinozan concepts of divinity was hugely-and perhaps essentially-political. Spinoza argues that the deity of popular superst.i.tion is a prop for theocratic tyranny. But what Spinoza calls theocratic oppression Leibniz identifies as the best of all possible systems of government. Thus, Leibniz turns the tables and calls Spinoza's concept of G.o.d "bad" and "dangerous," on the grounds that it will lead only to "out-and-out anarchy." His own concept of G.o.d, Leibniz a.s.sures us, will protect civilization-indeed, it will serve as the basis for a Christian republic united under a single church.

Leibniz's insistence on political implications of the metaphysics of divinity is so forceful that it raises the question as to whether his entire philosophy, like Spinoza's perhaps, was essentially a political project. For, inasmuch as it is the universal belief belief in the goodness of G.o.d that brings about the desired political ends of unity, stability, and charity, then the facts of the matter-whether G.o.d does indeed make choices and is good-don't matter at all. Philosophy, on this a.s.sumption, is not the disinterested search for the truth about G.o.d, but a highly sophisticated form of political rhetoric. in the goodness of G.o.d that brings about the desired political ends of unity, stability, and charity, then the facts of the matter-whether G.o.d does indeed make choices and is good-don't matter at all. Philosophy, on this a.s.sumption, is not the disinterested search for the truth about G.o.d, but a highly sophisticated form of political rhetoric.

Mind Modernity dethrones humankind. It reduces all our thoughts, purposes, and hopes to the object of scientific inquiry. It makes laboratory rats of us all. Spinoza actively embraces this collapse of the human into mere nature. Leibniz abhors it. Even more than he wants to convince us that G.o.d is good, Leibniz intends to demonstrate that we are the most special of all beings in nature. In the entire universe, he says, there is nothing more real or more permanent or more worthy of love than the individual human soul. We belong to the innermost reality of things. The human being is the new G.o.d, he announces: Each of us is "a small divinity and eminently a universe: G.o.d in ectype and the universe in prototype." This is the idea that defines Leibniz's philosophy, and that explains the enormous, if often unacknowledged, influence that his thought has wielded in the past three centuries of human history.

The greatest obstacle Leibniz confronts in his quest to deify the human being is Spinoza's theory of mind. In Spinoza's view, the mind is nothing real; it is merely an abstraction over the material processes of the body. But, counters Leibniz, in the material world, nothing lasts forever; everything is at the mercy of impersonal forces; what pa.s.ses for "unity" is merely temporary aggregation; and "ident.i.ty" is a chimera in the never-ending flux of becoming and pa.s.sing away. If Spinoza is correct, Leibniz concludes, then the human being, too, is merely chaff blowing in the silent winds of nature.

Leibniz's metaphysics is thus best understood as the effort to demonstrate, against Spinoza, that there is another world that is prior to and const.i.tutes the material world; that this more real real reality consists of indestructible, self-identical unities; and that we ourselves-in virtue of our having minds- reality consists of indestructible, self-identical unities; and that we ourselves-in virtue of our having minds-are the immaterial const.i.tuents of this more-than-real world. Of course, as a defender of the immaterial mind, Leibniz now faces the Cartesian mind-body problem in its full glory: He must explain how it happens that the immaterial mind at least appears to interact with the less-than-real material world. So, more precisely, his metaphysics may be understood as an attempt to solve the Cartesian mind-body problem in such a manner as to avoid falling into Spinozistic heresy. the immaterial const.i.tuents of this more-than-real world. Of course, as a defender of the immaterial mind, Leibniz now faces the Cartesian mind-body problem in its full glory: He must explain how it happens that the immaterial mind at least appears to interact with the less-than-real material world. So, more precisely, his metaphysics may be understood as an attempt to solve the Cartesian mind-body problem in such a manner as to avoid falling into Spinozistic heresy.

IN ORDER TO rid the world of Spinoza's theory of mind, Leibniz must first annihilate Spinoza's idea of Substance. For, in declaring that G.o.d alone is Substance, Spinoza reduces human beings to mere modes of Substance, and thereby renders our minds material and mortal. Leibniz's strategy is therefore to replace the doctrine that G.o.d alone is Substance with the claim that there is a plurality of substances in the world. By identifying the mind with these new substances, Leibniz intends to secure for humankind a degree of indestructibility, power, and freedom that his rival philosopher a.s.sociates only with G.o.d. In one of his rare later comments on Spinoza, Leibniz neatly summarizes the difference between the two philosophers on this fundamental point. The author of the rid the world of Spinoza's theory of mind, Leibniz must first annihilate Spinoza's idea of Substance. For, in declaring that G.o.d alone is Substance, Spinoza reduces human beings to mere modes of Substance, and thereby renders our minds material and mortal. Leibniz's strategy is therefore to replace the doctrine that G.o.d alone is Substance with the claim that there is a plurality of substances in the world. By identifying the mind with these new substances, Leibniz intends to secure for humankind a degree of indestructibility, power, and freedom that his rival philosopher a.s.sociates only with G.o.d. In one of his rare later comments on Spinoza, Leibniz neatly summarizes the difference between the two philosophers on this fundamental point. The author of the Ethics Ethics, as we know, scoffs at those who regard the human mind as "a kingdom within a kingdom," for, in his view, there is only one kingdom of Nature, one Substance. To which Leibniz responds: "My view is that every substance whatsoever is a kingdom within a kingdom."

The hunch that the world is made up of a plurality of substances appears in some of Leibniz's earliest writings. In the context of his reading of Spinoza's writings upon his return from The Hague, however, he formulates his view in a transparent way. In his notes on Spinoza's letters to Oldenburg as well as on his copy of the Opera Posthuma Opera Posthuma, Leibniz explicitly rejects Spinoza's definition of "substance" as that which is "in itself" and and "conceived through itself." The second part of the definition, he now a.s.serts, is incorrect: A substance must be "in itself," but it need not be "conceived through itself." Rather, it may be "conceived through G.o.d." "conceived through itself." The second part of the definition, he now a.s.serts, is incorrect: A substance must be "in itself," but it need not be "conceived through itself." Rather, it may be "conceived through G.o.d."

An obscure point, it would seem; and yet, if true, it destroys the proof of the Proposition 5 in Part I of the Ethics Ethics that there cannot be two or more substances in the world. For, that proof turns on the claim that two substances which are "conceived through themselves" can have nothing in common and so cannot be part of the same universe. It is no coincidence, then, that the proposition of the that there cannot be two or more substances in the world. For, that proof turns on the claim that two substances which are "conceived through themselves" can have nothing in common and so cannot be part of the same universe. It is no coincidence, then, that the proposition of the Ethics Ethics whose proof Leibniz seeks in his first letter to Schuller upon getting to Hanover is Proposition 5 of Part I of the whose proof Leibniz seeks in his first letter to Schuller upon getting to Hanover is Proposition 5 of Part I of the Ethics Ethics. If he can find the weak point in Spinoza's proof, Leibniz thinks, he will open up the tantalizing possibility that there is not one but a plurality of substances in the world. He further infers-on the basis of quasi-mathematical arguments that would require several more books to elucidate-that the number of such substances must be infinite for roughly the same reason that the number of points on a line is infinite. No matter how small a slice of the universe you take, he says, it will contain an infinite number of substances. In writings dating from the 1690s, he dubs these substances with a name derived from the Greek for "unity," first used by his predecessor Giordano Bruno, and which has since become famous: monads.

The claim that reality consists of an infinite number of monads entails some astonishing consequences, and Leibniz is not shy to draw these out. As substances, for example, monads must be entirely self-contained. That is, they depend on nothing else to be what they are. The most important implication of this is that they cannot interact with one another in any way at all-for, if they did so, one monad could conceivably alter the nature of another monad, and this would imply that its nature depends on the activity of some other substance, which, by the definition of substance, is not permissible. Thus, monads are-in Leibniz's notably poetic language-"windowless." They can't see out, and you can't see in.

It also follows that monads are immortal-they are always what they were and will be, namely, themselves. They have no beginning and no end. In order to make room for G.o.d, perhaps, Leibniz somewhat mysteriously allows that at the moment of creation, all monads came into being together, in a single "flash" and if they should disappear, they must all vanish together in a comparable "flash" of annihilation.

Notwithstanding their evident durability and self-ident.i.ty, monads do experience change of a sort, for they possess a capability to develop or "realize" themselves according to purely internal principles. In Leibniz's lyrical terms, they are "big [in the sense of "pregnant"] with the future." They may exist in the form of "seeds," he suggests, such as those observed in human s.e.m.e.n by scientists such as Jan Swammerdam and Antoni von Leeuwenhoek (both of whom Leibniz met on his journey through Holland).

Here Leibniz appeals to contemporary scientific findings in a manner that cannot but recall the practice of those modern philosophers who likewise attempt to substantiate their metaphysical claims with reference to recent scientific discoveries (in our time, usually quantum mechanics). The rocket science of Leibniz's time was microscopy. The work of the Dutch pioneers in the field, says Leibniz, demonstrates that there are tiny animals everywhere-animals within animals-on no matter how small a scale one looks. Therefore, he concludes, it is quite plausible-nay, practically certain-that if these tiny animals had microscopes, they, too, would find even tinier animals, and so on all the way down without end.

Although all monads exist forever, they nonetheless seem to perdure in the context of very different fellow-monad structures over time. The Leibniz monad, for instance, existed in seed form from the beginning of time. Contrary to popular prejudice, what it acquired on July 1, 1646, was only the agglomeration of fellow monads that make up its outward body. (The fact that Leibniz had two parents vexed the philosopher's followers-who had the monad, mom or dad?-but they did their best to overcome the "problem of s.e.x.") Furthermore, as scientists have shown that even in fires small particles of ash survive in the smoke, it is evident that the Leibniz monad, like its brother monads, will continue to exist indefinitely in microscopic form-perhaps wafting on a piece of dust around its favorite city of Paris, where it will enjoy memories of happier days and receive from G.o.d the rewards and punishments appropriate to its deeds.

One of the most striking and controversial inferences that Leibniz draws from the substantial nature of the monad is that a monad's future is written into its essence from the very beginning of things. He expresses this daring doctrine in terms of logic as well as metaphysics. The "complete" concept of a substance, he says, must contain all the predicates that ever have been and ever will be true of it. For example-and here he invites much aggravation from his critics-the complete concept of "Caesar" ever and always includes the predicate "crossed the Rubicon" just as the complete concept of "Leibniz," presumably, ever and always includes the predicate "visited Spinoza in The Hague." A monad, one could say, is the ideal subject for a biography: its entire life story unfolds with absolute logical necessity from its singular essence; and so the biographer need only locate this essence in order to settle on an appropriate plot and chapter outline.

The life of a monad does not seem as solitary as it in fact is. Each monad, according to Leibniz, has within itself a "mirror" of the entire universe-a picture of what is happening everywhere at all times and how its own activities "fit in." Thus, monads are essentially mindlike. That is, they have a faculty of perception perception that constructs for them a picture of the "external" world, and a faculty of that constructs for them a picture of the "external" world, and a faculty of apperception apperception that registers an awareness of this process of perception itself. that registers an awareness of this process of perception itself.

By means of these "mirrors" of consciousness, each monad replicates the entire universe of monads within itself; and so each monad is a "universe in prototype." Leibniz refers to this strange vision of worlds within worlds as "the principle of macrocosm and microcosm"-meaning that the microcosm contains or replicates the macrocosm all the way down to the infinitely small. He expresses the same notion in his claim that the ancient doctrine that "All is One" must now be supplemented with the equally important corollary that "One is All."

If Leibniz had been writing in the information age, incidentally, he very likely would have replaced the monad mirrors with laptops running interactive virtual-reality software. Such a metaphor perhaps better conveys the sense in which monads interact with a wider universe only in an internal, "virtual" way, since they cannot really have contact with the rest of the universe at all.

The monad mirrors, in any case, are somewhat scratched and imperfect-no doubt like the silver-backed mirrors that would have caught the philosopher's gaze in Paris. (Or, one could say, the virtual-reality screens have low resolution; or, the software still has lots of bugs.) So, all monads have a confused perception of the world around them. (Save G.o.d, of course, whose version of Windows is perfect).

It is the logic of his system-and not arbitrary fancy nor a theory of the subconscious mind, as some have suggested-that compels Leibniz to scratch the mirrors of his monads. The imperfections in individual monads' perceptions play a key role in distinguishing one monad from another, for it is the partial perspective of each monad on the totality that makes it a unique individual with a unique "point of view" as it were. This is what Leibniz means when he says that a monad subsists "in itself" but is not necessarily "conceived through itself." To put it another way: two monads with absolutely perspicuous knowledge of the entire universe would be indistinguishable-in fact, they would both be G.o.d, or that through which all substances are conceived.

Equally important, the splotchiness in the mirrors creates the possibility of "free will" in monads, or so Leibniz contends. Although the entire past and future of a monad are embedded in its complete concept, nonetheless, on account of the inferior optics, a monad cannot understand its own essence in a fully perspicuous way. Because it does not know its own future (as G.o.d does), the monad is forced to make decisions and behave as though it were free. So, for example, G.o.d knew through all eternity that Leibniz was going to visit Spinoza in The Hague; but when Leibniz got off the boat, he faced a choice between walking over to the Paviljoensgracht and stopping in a local coffeehouse for the afternoon.

The obscurity in the monad mirrors, finally, allows us to explain the crucial differences among types of monads. Although in the final a.n.a.lysis monads differ in degree and not kind, they nonetheless fall roughly into three groups, corresponding to what we may think of as rocks, animals, and people. All monads are mindlike to some degree, but only the peoplelike monads have minds, properly speaking. That is, their mirrors-their faculties of perception and apperception-are developed to the point where they have memory and self-awareness. Animal monads have souls, but not minds, strictly speaking, for their apperception or self-awareness tends to be lacking (Leibniz is a little vague on the point; but, in any case, it is worth noting that, compared with the dog-beating Cartesians, he was practically an animal-rights activist, insisting that it is repugnant to view animals as mere machines.) Rocklike monads are extremely pa.s.sive, and so Leibniz has little to say about them. Note, however, that what we think of as an individual human being consists of one mind-monad dominating an infinite, swirling agglomeration of rocklike body-monads.

With this last observation, the main point of the strange fable of the monads begins to come into focus. Leibniz's purpose is to lay out the context within which the Cartesian mind-body problem may be resolved and the immateriality of the mind preserved against Spinoza's soul-destroying Substance. In the new vocabulary of monads, the mind-body problem may be restated thus: How do mind-monads coordinate their activities with body-monads so that all work together to create a coherent universe in which minds and bodies appear to interact? For example: How is it that, when the Leibniz mind-monad decides to meet Spinoza in The Hague, his body-monads get him aboard the yacht, walk him down along the ca.n.a.ls, and knock on his fellow philosopher's door? And how is it that the equally self-contained Spinoza monad happens to organize its body-monads in such a way as to open the door for his visitor?

Phrased in these terms, now, it is evident that, within the Leibnizian system, the mind-body problem no longer refers to something that is logically impossible, but only to something that seems ludicrously improbable. That is, Leibniz does not have to explain how two radically different cla.s.ses of ent.i.ty-minds and bodies-may interact with each other; he simply takes it as given that all substances are of the same mindlike nature and that they do not interact with one another at all. The remaining problem is only that it seems very unlikely, to say the least, that all these monads would coordinate their internally driven activities in such a way as to produce a coherent world-that the Leibniz mind-monad should not decide to visit Spinoza, for example, while the rest of him goes for a cup of coffee.

This understanding of the problem sets the stage for what Leibniz claims is his single most magnificent bequest to humanity: the doctrine of "the pre-established harmony." Although each monad acts according to its own, purely internal laws of development, Leibniz maintains, each is so designed that the world within which it perceives itself to be acting coheres exactly with the world within which all the other monads perceive themselves to be acting. Thus, for example, when the Leibniz mind-monad decides to call on Spinoza, the Leibniz body-monads just happen to be planning a walk up the Paviljoensgracht, too.

Leibniz's choice of a musical metaphor to describe the coordination of monad activities seems very much in the spirit of his age. In the late seventeenth century, the delights of contrapuntal music became widely celebrated, great architecture was praised as "frozen music," and even the orbits of the planets around the sun were said to have agreeably musical properties. Sometimes, though, Leibniz uses a different metaphor, one drawn from another of the wonders of his age: the watch. Mind and body, he says, are like a pair of perfectly constructed and perfectly synchronized watches. They tell the same time throughout eternity, not because they are causally linked to each other, nor because anyone intervenes to adjust one to the other, but because each on its own progresses through the same series of seconds on its own devices. (It is interesting to note that in Leibniz's day watches were notoriously imprecise, and could be counted on to diverge appreciably from one another by the end of each working day; but the race was on to build one of sufficient reliability to be used in measuring the longitude of ships at sea.) In the information age, we would probably favor a different metaphor: although each monad runs its own virtual-reality software on a stand-alone basis, we could say, the virtual reality of each monad is perfectly consistent with the virtual realities of all the other monads.

Needless to say, the extraordinary degree of mutual compatibility among monads is far greater than could ever be attributed to any merely human watchmaker or even any immortal software corporation. In fact, says Leibniz, the pre-established harmony is manifestly the handiwork of G.o.d. When the Almighty creates the infinite infinity of monads in the big flash, he designs each in such a way that its internal principle of activity harmonizes perfectly with those of all the others. The doctrine of the pre-established harmony may also be understood as a generalized and perhaps more elegant version of Malebranche's occasionalism. According to the latter, G.o.d intervenes on every occasion where there is an interaction of mind and body, in an endless series of real-time miracles. In Leibniz's world, G.o.d intervenes only once, at the moment of creation, in an original miracle whereby he programs the infinite infinity of monads with such astonishing skill that they sing in harmony for all eternity.

The pre-established harmony also lines up neatly as the apparent replacement for Spinoza's doctrine of parallelism. Spinoza, we should recall, claims that mind and body operate in parallel because they are really the same thing seen from two angles, like two sides of the same coin. Leibniz implicitly agrees that mind and body appear to operate in parallel, like two clocks ticking away side by side; but, on his account, they do so only by the grace of G.o.d's impeccable craftsmanship, for they are in themselves radically independent of each other.

G.o.d's intervention on the mind-body problem is so wondrous, Leibniz adds, that it amounts to another proof of his existence and of his goodness. The proof belongs to an ancient theological tradition, one that flared in the seventeenth century but that has always smoldered somewhere in the hearth of the human imagination. Leibniz's question-How is it that all the monads manage to get along so well?-is a generalization over some much simpler questions that have been asked many times before: How is it that apples are just the right size for our mouths? How is it that the water we need to live falls so abundantly from the sky? With minor changes in vocabulary, the same type of question may be heard in places even today: How is it that the apparently arbitrary parameters of the physical laws of the universe, some would ask, are set at precisely those values that make life in the universe possible? How can such complex phenomena as intelligent life be the result of an evolutionary process that has no purpose or designer? The argument that only G.o.d could account for such improbable developments as bite-sized apples, congenial cosmological constants, intelligent life, and the pre-established harmony is generally called "the argument from design." Spinoza, Hume, Kant, and many other philosophers have long since pointed out that the logic of the argument is hardly compelling: it establishes a probability, not a certainty; and the probability of an event that is absolutely unique is in any case indefinable. But, as Leibniz understood, mere quibbles about logic do little to diminish the enduring appeal of the argument.

The story about monads and the pre-established harmony clearly reinforces-and is intended to reinforce-Leibniz's political vision. To the respublica Christiana respublica Christiana and the Empire of Reason, Leibniz now adds a third name for his political ideal: the City of G.o.d. The citizens of this heavenly metropolis, he says, are the thinking monads of the world-i.e., all people-and the harmony they exhibit among themselves is a reflection of G.o.d's glory. A pillar of the theocratic order represented in the City of G.o.d is the doctrine of personal immortality encoded in the monadology. Indeed, Leibniz maintains that without universal belief in rewards and punishments in the afterlife, people will behave very badly and anarchy will consume society. Thus, at stake in his refutation of Spinoza's theory of mind is the preservation of Christian civilization. and the Empire of Reason, Leibniz now adds a third name for his political ideal: the City of G.o.d. The citizens of this heavenly metropolis, he says, are the thinking monads of the world-i.e., all people-and the harmony they exhibit among themselves is a reflection of G.o.d's glory. A pillar of the theocratic order represented in the City of G.o.d is the doctrine of personal immortality encoded in the monadology. Indeed, Leibniz maintains that without universal belief in rewards and punishments in the afterlife, people will behave very badly and anarchy will consume society. Thus, at stake in his refutation of Spinoza's theory of mind is the preservation of Christian civilization.

Yet, notwithstanding their creator's medieval-sounding politics, Leibniz's monads have a curiously modern edge, too. The City of G.o.d is a monarchy, to be sure, with G.o.d as its king. But, among its earthly denizens, a certain kind of egalitarianism reigns. All monads are created equal; each embodies the All, and each reflects the full glory of G.o.d; and so each has certain basic rights of citizenship. Indeed, Leibniz specifically opposes slavery, for example, on the basis of the equality of monads. The universal equality of monads also finds expression in Leibniz's thoroughgoing cosmopolitanism: "Justice is that which is useful to the community, and the public good is the supreme law-a community, however, let it be recalled, not of a few, not of a particular nation, but of all those who are part of the City of G.o.d and, so to speak, of the state of the universe." Although Leibniz's legacy was later commandeered by Germans in the name of nation building, the philosopher himself never wavered from the universality of his ideal. In the context of a tiff among the various European academies, for example, he writes: "Provided something of consequence is achieved, I am indifferent whether this is done in Germany or France, for I seek the good of mankind. I am neither a phil-h.e.l.lene nor a phil-Roman, but a phil-anthropos."

Leibniz was indeed a phil-anthropos, and this was perhaps both the central message embedded in his monadology and the chief point of contrast with the reviled Spinoza. For, according to the latter, the human being is nothing exceptional, and it is merely ignorance and vanity that lead humankind to imagine that we "are the largest part of nature." But, according to Leibniz, the human being is everything-the point and the substance of the world. The modern secular state, when viewed from a global perspective, looks much more like Spinoza's free republic than Leibniz's City of G.o.d; and yet, paradoxically, many of the beliefs that guide individuals within the modern world-the faith in the sanct.i.ty of the individual, the ideal of charity, and the unique purpose of humankind-would seem to follow directly from Leibniz's essentially antimodern theocratic project.

One the most intriguing features of Leibniz's monadological vision is the most obvious one: that it seems to describe an ideal ideal. The City of G.o.d serves Leibniz as a vision whose realization is the goal of all of his efforts (and those of like-minded individuals). In some pa.s.sages, Leibniz even makes this rather modern notion of progress explicit: "We must also recognize that the entire universe is involved in a perpetual and most free progress, so that it is always advancing toward greater culture." And yet, logically speaking, the City of G.o.d is a representation of the actual world, not of an ideal one. We are are monads, after all; we are already immortal and we necessarily live according to the laws of the pre-established harmony. This conflation of-or perhaps confusion between-representations of the real and depictions of the ideal is a fundamental feature of Leibnizian metaphysics, and perhaps even raises the question as to whether the entire system of monads and harmonies was less a representation of life as we know it than some sort of visionary utopia. monads, after all; we are already immortal and we necessarily live according to the laws of the pre-established harmony. This conflation of-or perhaps confusion between-representations of the real and depictions of the ideal is a fundamental feature of Leibnizian metaphysics, and perhaps even raises the question as to whether the entire system of monads and harmonies was less a representation of life as we know it than some sort of visionary utopia.

"ALL THIS, I acknowledge, I understand not at all," wrote the English philosopher Samuel Clarke in response to Leibniz's attempt to explain his ideas about substances and the pre-established harmony, and there is no shame in admitting as much even today when presented with the monadological philosophy in bare outline. Bertrand Russell frankly confesses that, on first reading, Leibniz's metaphysics struck him as "a fascinating fairy tale, coherent, perhaps, but wholly arbitrary." Possibly Hegel provides the most useful guidance on the matter: "Leibniz's philosophy appears like a string of arbitrary a.s.sertions, which follow one another like a metaphysical romance," he acknowledges. "It is only when we see what he wished thereby to avoid that we learn to appreciate its value." acknowledge, I understand not at all," wrote the English philosopher Samuel Clarke in response to Leibniz's attempt to explain his ideas about substances and the pre-established harmony, and there is no shame in admitting as much even today when presented with the monadological philosophy in bare outline. Bertrand Russell frankly confesses that, on first reading, Leibniz's metaphysics struck him as "a fascinating fairy tale, coherent, perhaps, but wholly arbitrary." Possibly Hegel provides the most useful guidance on the matter: "Leibniz's philosophy appears like a string of arbitrary a.s.sertions, which follow one another like a metaphysical romance," he acknowledges. "It is only when we see what he wished thereby to avoid that we learn to appreciate its value."

There is in fact a single thread that may lead one safely through the labyrinth of the monadology. The astonishing and bizarre features of the monads-the windowlessness, the pregnancies, the splotchy mirrors, the infinite replications of the infinite universe, and the pre-established harmony-all follow with admirable logical rigor from the premise that substantiality (i.e., absolute unity, self-ident.i.ty, freedom, and permanence) is a quality of individual minds, and not of nature as a whole. What Leibniz is for for is often difficult to grasp; but what he is is often difficult to grasp; but what he is against against fits neatly into one word: Spinoza. fits neatly into one word: Spinoza.

Salvation Leibniz, like Spinoza, finds happiness in the love of G.o.d. But, as the two philosophers have very different ideas about the nature of both G.o.d and love, they inevitably arrive at very different destinations on their respective journeys to salvation.

According to Spinoza virtue is its own reward. Therefore, the question of personal immortality can have no bearing on our salvation, for the wise man has no need of additional rewards in a purported afterlife to justify virtue in this life. Leibniz, on the other hand, takes the more usual view that in this life, at least, virtue often goes unrewarded, and evil often goes unpunished. Belief in the immortality of the soul, he argues, is therefore essential if we are to have faith that the calculus of rewards and punishments in the universe will ever add up to justice. The doctrine of personal immortality is thus vital to our happiness. Indeed, says Leibniz, Spinoza's attack on the doctrine of personal immortality, if successful, can serve only to bring great misery to the human race. (It is curious to note once again that, according to the logic of Leibniz's arguments, it is the belief belief in and not the in and not the fact fact of immortality that matters for our happiness. Even if the soul were mortal, we could still find a Leibnizian kind of bliss, provided we were able to convince ourselves otherwise.) of immortality that matters for our happiness. Even if the soul were mortal, we could still find a Leibnizian kind of bliss, provided we were able to convince ourselves otherwise.) The difference between Leibniz and Spinoza on happiness, as on all subjects, comes down to their different att.i.tudes toward G.o.d. For Spinoza, the intellectual love of G.o.d is the highest form of reason. But, as we know, this brainy love is not of the kind that can be returned. Spinoza's Substance is utterly indifferent to humanity's concerns. For Leibniz, on the other hand, the only love worthy of the name is the kind that promises punctual and copious repayment. Spinoza's unrequited love of G.o.d, Leibniz maintains, is in fact unreasonable unreasonable: Spinoza thinks that the mind can be greatly strengthened if it understands that what happens, happens necessarily. But the animus of the sufferer is not rendered content through his compulsion, nor does it feel evils any the less on that account. The soul is happy if it understands that good follows from evil, and that what happens is for the best if we have wisdom.

In the Theodicy Theodicy he adds that Spinozistic dogmas concerning the "brutish" necessity of things "destroy the confidence in G.o.d that gives us tranquility, the love of G.o.d that makes our happiness." His own doctrines, by contrast, guarantee that G.o.d does everything with our good in mind, and thus they give us the happiness and tranquility we need. The crucial difference between the two philosophers comes down to this: Spinoza finds happiness in loving G.o.d; Leibniz finds it in G.o.d loving us back. (Or, again, more precisely, Leibniz finds happiness in the he adds that Spinozistic dogmas concerning the "brutish" necessity of things "destroy the confidence in G.o.d that gives us tranquility, the love of G.o.d that makes our happiness." His own doctrines, by contrast, guarantee that G.o.d does everything with our good in mind, and thus they give us the happiness and tranquility we need. The crucial difference between the two philosophers comes down to this: Spinoza finds happiness in loving G.o.d; Leibniz finds it in G.o.d loving us back. (Or, again, more precisely, Leibniz finds happiness in the belief belief that G.o.d loves us back.) that G.o.d loves us back.)

LEIBNIZ'S META PHYSICS, no less than Spinoza's, is a personal confession and involuntary memoir-a kind of ontological hologram of the character of its creator. With its agile synthesis of an extraordinary range of philosophical issues and ideas, it reflects the highest aspirations of Guilielmus Pacidius, the Great Peacemaker of All Thought. In its fantastical and poetic moments, it captures something of the richness of the imaginary life of the man who conceived of the Egypt Plan and sparred with windmills. With the impossibly intricate arrangement of its many moving parts, it embodies the incomparable cleverness of the inventor of the most advanced arithmetical calculating machine of his day. In its excess of ingenuity-for it can hardly be overlooked that the system is sometimes no less than Spinoza's, is a personal confession and involuntary memoir-a kind of ontological hologram of the character of its creator. With its agile synthesis of an extraordinary range of philosophical issues and ideas, it reflects the highest aspirations of Guilielmus Pacidius, the Great Peacemaker of All Thought. In its fantastical and poetic moments, it captures something of the richness of the imaginary life of the man who conceived of the Egypt Plan and sparred with windmills. With the impossibly intricate arrangement of its many moving parts, it embodies the incomparable cleverness of the inventor of the most advanced arithmetical calculating machine of his day. In its excess of ingenuity-for it can hardly be overlooked that the system is sometimes too too clever-it mirrors something of the philosopher's irrepressible vanity. Its very quirkiness reads like a signature-Leibniz's way of reminding the world that this was clever-it mirrors something of the philosopher's irrepressible vanity. Its very quirkiness reads like a signature-Leibniz's way of reminding the world that this was his his system. system.

There is in the monadology, too, something of that legalistic sensibility-the strange gap between the author and his own arguments so characteristic of Leibniz from his earliest works. As ever, the philosopher evinces surprise and delight in his own ratiocinations; words like "advantageous," "useful," and "pleasing" trip lightly off his tongue. In all of his philosophical investigations, he never discovers the kind of thing that others might call a "grim truth." He is always the lawyer-a highly polished, politically appointed public defender, with tremendous courtroom presence and a knack for parsing culpability with infinitely refined distinctions. He leaves us in no doubt as to what it is that he would like us to believe. Yet he can never entirely avoid raising a nagging question as to whether he he believes what he says. believes what he says.

Was Leibniz in his heart of hearts truly convinced that reality consists of an infinity of pregnant, windowless, splotchy substances? Or was he just rustling up the theory of the case that would rescue G.o.d from the seemingly inevitable verdict of malpractice?

Whether he believed it or not may be impossible to determine; but the fact that he would have liked would have liked to believe in his monadological world seems quite certain. The philosophy of Leibniz expresses, above all, the neediness of its creator. His is essentially a metaphysics of rea.s.surance, intended to strengthen within us the comforting convictions that G.o.d cares for us, that we never die, and that all is for the best in the best of all possible worlds. At some level, it surely represents the mature philosopher's answer to the craving for security and the longing for paternal guidance that he first bared to the world as a schoolboy. And it is this all too human cry from the heart that made his work so universal in the later history of philosophy. to believe in his monadological world seems quite certain. The philosophy of Leibniz expresses, above all, the neediness of its creator. His is essentially a metaphysics of rea.s.surance, intended to strengthen within us the comforting convictions that G.o.d cares for us, that we never die, and that all is for the best in the best of all possible worlds. At some level, it surely represents the mature philosopher's answer to the craving for security and the longing for paternal guidance that he first bared to the world as a schoolboy. And it is this all too human cry from the heart that made his work so universal in the later history of philosophy.

Leibniz, perhaps alone with Spinoza, grasped the general direction of modern history. But, unlike his eerily self-sufficient rival, he had a far greater concern with the price that humanity would have to pay for its own progress. He understood that even as science tells us more and more about what what everything is, it seems to tell us less and less everything is, it seems to tell us less and less why why; that even as technology reveals utility in all things, it seems to find purpose in nothing; that as humanity extends its powers without limit, it loses its faith in the value of the same beings who exercise that power; and that, in making self-interest the foundation of society, modern humankind finds itself pining for the transcendent goals that give life any interest at all. Leibniz saw modernity in the first instance as a threat rather than an opportunity. In all of his philosophical labors, his aim was to protect our sense of purpose and self-esteem from this threat, to rescue an old set of values from the depredations of the new. And there was no more dangerous and powerful exponent of the new than Spinoza.

Leibniz's mature metaphysics, in brief, was a confrontation with the philosophy of the man he met in The Hague. Yet Leibniz did not consolidate his mature views until ten years after the encounter. The spectacular artifice of the monadology was the fruit of a debate that took place in his own mind with an interlocutor long since dead. It reflects what he might have wished had happened in the house on the Paviljoensgracht, perhaps, but not what actually occurred. In fact, it reads like the interior monologue of one who keeps reliving a certain moment, replaying the event from different angles, rehearsing his own responses, adding voice-over commentary, tweaking his memories and editing key pa.s.sages until at last, on final playback, he scores the victory that he longs to believe was rightfully his.

15.

The Haunting "I can't tell you how distracted a life I am leading," Leibniz confided to one of his friends in late middle age. "I have so much that is new in mathematics, so many thoughts in philosophy, so numerous literary observations of other kinds, which I do not wish to lose, that I am often at a loss what to do first...." can't tell you how distracted a life I am leading," Leibniz confided to one of his friends in late middle age. "I have so much that is new in mathematics, so many thoughts in philosophy, so numerous literary observations of other kinds, which I do not wish to lose, that I am often at a loss what to do first...."

The first item on his list of distractions was a genealogy. Following the implosion of his mining venture, Leibniz needed a new peg on which to hang his hopes for career security. He proposed to Duke Ernst August that a thorough history of the Brunswick clan would enhance the prestige of the Duchy of Hanover, and the Duke happily appointed him as the family historian. In return for performing the labor, Leibniz suggested, the Duke should double his salary. In the event, he settled for having his existing salary converted to a pension for life.

It proved to be less of a bargain than Leibniz might have hoped. After forty years of rolling the genealogical stone up the hill only to have it fall back down on top of him, the philosopher managed to bring the history of the Brunswicks only up to the eleventh century. But the project did offer one overwhelming benefit: It gave Leibniz the excuse to leave Hanover. At the age of forty-one, he set off on what he promised his employers would be a two-and-a-half-month journey for the purpose of gathering genealogical data from royal houses in Germany and Italy. He stopped in dozens of cities and towns all the way down to Naples; took in renowned collections of coins, fossils, and caterpillars; attended private showings of operas; visited all the major libraries; met with leading experts on China, Kabbalism, mining technology, chemistry, mathematics, and anatomy; and returned home two and a half years later with a carefully tallied bill of 2,300 thalers in expenses and a fistful of somewhat defensive-sounding letters in which he insisted that he had performed no inconsiderable labor on behalf of the Duke of Hanover during his travels.

Leibniz's political activities, too, consumed much of his energy in his years of plenty. At the age of fifty, in recognition of his able a.s.sistance in, among other things, securing the elevation of the Duke of Hanover to Elector of the Holy Roman Empire, he was promoted to privy counselor of justice, the second-highest civil rank in the land. His incessant pet.i.tions for increases in pay began to meet with occasional success. Including the income from moonlighting with neighboring princ.i.p.alities, his receipts rose to a vertiginous 2,000 thalers per year-11 Spinoza Units. When he eventually got the Society of the Sciences going in Berlin and became its first president, he began to draw another 600 thalers annually from that source. By the standards of the time, he was becoming a very wealthy man.

In his later years, the great philosopher also devoted much time to cultivating his friendships with the ladies of the court, notably d.u.c.h.ess (later Electress) Sophia and her daughter, Sophia Charlotte, the first queen of Prussia. Sophia had two things her husband, Duke Ernst August, conspicuously lacked: a sense of humor and an interest in philosophy. Upon reading Spinoza's Tractatus Tractatus in 1679, for example, she declared it "admirable" and "completely in accord with reason." She enthused that her second son, Friedrich August, "knows Descartes and Spinoza almost by heart" and regarded her eldest, Georg Ludwig-the future King George I of England-as the thick one on account of his lack of interest in metaphysics. When she learned of Spinoza's death, she quipped that a churchman must have poisoned him, because "most of the human race lives by deceit." in 1679, for example, she declared it "admirable" and "completely in accord with reason." She enthused that her second son, Friedrich August, "knows Descartes and Spinoza almost by heart" and regarded her eldest, Georg Ludwig-the future King George I of England-as the thick one on account of his lack of interest in metaphysics. When she learned of Spinoza's death, she quipped that a churchman must have poisoned him, because "most of the human race lives by deceit."

Leibniz later said that his Theodicy Theodicy was the record of conversations he had with Sophia's daughter, Sophia Charlotte, in the gardens of the family's summer palace. Sophia Charlotte, it seems, was even more of a handful than her mother. "Here is a letter of Leibniz," she pouts to a friend. "I love this man; but I am angry that he treats everything so superficially with me." On her deathbed, according to the legend pa.s.sed on by her grandson, Frederick the Great, the still vivacious queen is reported to have said to the hovering prelates: "Do not torment me, for I go now to satisfy my curiosity on the principle of things that Leibniz has never been able to explain to me; on s.p.a.ce, infinity, being, and nothingness. And I prepare for my husband the King the spectacle of a funeral, where he will have a new opportunity to display his grandeur." was the record of conversations he had with Sophia's daughter, Sophia Charlotte, in the gardens of the family's summer palace. Sophia Charlotte, it seems, was even more of a handful than her mother. "Here is a letter of Leibniz," she pouts to a friend. "I love this man; but I am angry that he treats everything so superficially with me." On her deathbed, according to the legend pa.s.sed on by her grandson, Frederick the Great, the still vivacious queen is reported to have said to the hovering prelates: "Do not torment me, for I go now to satisfy my curiosity on the principle of things that Leibniz has never been able to explain to me; on s.p.a.ce, infinity, being, and nothingness. And I prepare for my husband the King the spectacle of a funeral, where he will have a new opportunity to display his grandeur."

Leibniz became so comfortable in the company of aristocrats that at some point it seems he decided to make himself one. His began to sign his letters with a small and illegible squiggle between his first and last names-a squiggle that grew in confidence until it unmistakably represented a v v, as in Gottfried Wilhelm von von Leibniz. But the courtier was never enn.o.bled, and there is no evidence that he ever brought himself to part with the money that would have been required to purchase such a distinction. Eventually, the squiggled enn.o.blement vanished from his letters as mysteriously as it had arisen. Leibniz. But the courtier was never enn.o.bled, and there is no evidence that he ever brought himself to part with the money that would have been required to purchase such a distinction. Eventually, the squiggled enn.o.blement vanished from his letters as mysteriously as it had arisen.

Notwithstanding the travel, the hack work, the chatty princesses, and all the other demands on his time, Leibniz in his later years never relented in the heroic level of his intellectual activity. He churned out hundreds of letters to learned correspondents every year; prepared treatises on chemistry, optics, economics, and "the true laws of matter" drafted up new problems and solutions in the "science of infinities" (i.e., the calculus); conducted thought experiments on the universal characteristic; performed intricate a.n.a.lyses of the theological issues at stake in church reunion; revised the entire system of laws in Germany; composed thousands of lines of Latin in poetry in perfect meter and rhyme; and tinkered with his arithmetical calculating machine, which he was sure would one day soon be ready for practical use.

The reckless curiosity, the tireless dedication to learned pursuits, the delight in subtle argumentation, the multiple and constantly shifting layers of motives, the insatiable hankering for security, the yearning for Paris or something like it, the careerism and the politicking, the ceaseless dance along the line that separates order from chaos, and all the rest of the dazzling, omnimaniacal Leibniz show continued without interruption for the remaining thirty years of the philosopher's life. As he grew older, Leibniz became more Leibniz.

One day in his later life, a young n.o.bleman visited the world's last great polymath and left us with an intimate portrait of the philosopher at home in his maturity: Although he is more than sixty years of age, and makes a strange appearance clad in fur stockings, a dressing gown lined with the same material, large socks made of felt, instead of slippers, and a long, singular looking wig, nevertheless he is a very polite and social person, and entertained us with remarks on politics and various literary topics. I succeeded at length in breaking off the conversation for the purpose of asking him to show me his library.... But, as I had been led to expect would be the case, he declined.... Other persons a.s.sured me, however, that the books in his library were very numerous and valuable; but that it was a peculiarity of Leibniz's, that he liked to worm in it alone. Not even the Elector himself, therefore, could get a chance of seeing it, the Herr Privy Counselor always alleging that it had not been put in order.

Leibniz's own writings from later life paint much the same portrait of a chatty, eccentric, and sometimes rambling elder statesman in the republic of letters. They read like the syllabus for an entire university written with the zest of a society tabloid. They reveal a mind crowded with memories of people, places, and ideas; fired with undiminished desire to know; and br.i.m.m.i.n.g with higher learning, political trivia, hot b.u.t.tons, and white lies.

The peculiar costume of fur and felt, incidentally, was Leibniz's one concession to age. From around his fiftieth year, he suffered increasingly from a painful form of arthritis. Quite sensibly, however, he avoided the doctors of the time-who, with their leeches and lancets and noxious potions did far more damage than the illnesses they purported to treat-and preferred instead to pursue a sartorial therapy of his own design.

With Leibniz, inevitably, as with almost all aging philosophers, a certain amount of intellectual sclerosis set in, too. In his later years, the elements of the metaphysical system he first outlined in the Discourse Discourse became so self-evident to him that he often saw no need to argue for them. They became a fixed part of his reality, and his deepest philosophical pleasure came less from formulating his propositions than from seeing their truth reflected back to him in the statements and activities of others. became so self-evident to him that he often saw no need to argue for them. They became a fixed part of his reality, and his deepest philosophical pleasure came less from formulating his propositions than from seeing their truth reflected back to him in the statements and activities of others.

Those who viewed the spectacle of the philosopher's performance from afar might well have supposed that the encounter in The Hague now belonged to the dead part of personal history; it was just another long forgotten scene in the endless variety show of his life. By the time of the Theodicy Theodicy in 1710, in fact, Leibniz virtually edited out of existence what little remained of the encounter in his letter to Count Ernst of 1683. The rendezvous with Spinoza now counted as the equivalent of a chance encounter at sea: "I saw M. de la Court as well as Spinoza on my return from France through England and Holland, and I learned from them some good anecdotes concerning affairs of those times." On the matter of his prior correspondence with Spinoza, Leibniz seemed content to put the subject to rest with a casual lie: "I wrote to him one time a letter concerning optics, which was inserted in his [posthumous] works." The claim that he wrote to the humble lens grinder "one time," of course, is directly contradicted by evidence contained in the very same volume of Spinoza's posthumous works. in 1710, in fact, Leibniz virtually edited out of existence what little remained of the encounter in his letter to Count Ernst of 1683. The rendezvous with Spinoza now counted as the equivalent of a chance encounter at sea: "I saw M. de la Court as well as Spinoza on my return from France through England and Holland, and I learned from them some good anecdotes concerning affairs of those times." On the matter of his prior correspondence with Spinoza, Leibniz seemed content to put the subject to rest with a casual lie: "I wrote to him one time a letter concerning optics, which was inserted in his [posthumous] works." The claim that he wrote to the humble lens grinder "one time," of course, is directly contradicted by evidence contained in the very same volume of Spinoza's posthumous works.

In his later philosophical writings, as a rule, Leibniz mentions the name of Spinoza only in the spirit of caricature. The "famous Jew" is almost always twinned with Hobbes, that other malefactor of modern materialistic atheism, and is reliably presented as the spokesperson for a patently absurd metaphysics of "brute necessity." "One need not refute an opinion so bad," he says in a typical comment on Spinoza's doctrine that G.o.d alone is Substance. He describes Spinoza's philosophy in general as "pitiful and unintelligible" and shows no interest in engaging his rival's arguments in any direct or detailed way. Year by year, his official posture on Spinoza calcified like the joints in his stiffening body.

But, behind Leibniz's ever shifting public facades, the ghost of Spinoza was far from leaving the courtier-philosopher in peace. At the core of Leibniz's restless endeavors lay a permanent anxiety. It was an anxiety that expressed itself in an astonishing variety of ways: in the frantic search for financial security and social status, in the dread of Hanoverian provincialism, in the desperate schemes for repairing a fractured church, in fears of political revolution, and in frenetic attacks on a range of fellow philosophers, from Descartes to Locke to Newton. But it was, at bottom, always the same anxiety. And, in the fullness of time, it came to acquire a name, a name that stood for everything that Leibniz could neither abide nor evade. In the forty years after he departed from The Hague, Leibniz was always running; but he was running in circles, never quite able to extricate himself from the orbit of the man he met in November 1676.

Church Reunion When Leibniz submitted a condensed version of his Discourse on Metaphysics Discourse on Metaphysics to Antoine Arnauld in 1686, his hopes were high that Protestants and Catholics would soon be taking communion together in a universal church. But Arnauld handed Leibniz a humiliating setback. To Count Ernst von Hessen-Rheinfels, who served as mediator in the discussion, the