STRANGER: Do we admit that virtue is distinct from vice in the soul?

THEAETETUS: Certainly.

STRANGER: And purification was to leave the good and to cast out whatever is bad?

THEAETETUS: True.

STRANGER: Then any taking away of evil from the soul may be properly called purification?

THEAETETUS: Yes.

STRANGER: And in the soul there are two kinds of evil.

THEAETETUS: What are they?

STRANGER: The one may be compared to disease in the body, the other to deformity.

THEAETETUS: I do not understand.

STRANGER: Perhaps you have never reflected that disease and discord are the same.

THEAETETUS: To this, again, I know not what I should reply.

STRANGER: Do you not conceive discord to be a dissolution of kindred elements, originating in some disagreement?

THEAETETUS: Just that.

STRANGER: And is deformity anything but the want of measure, which is always unsightly?

THEAETETUS: Exactly.

STRANGER: And do we not see that opinion is opposed to desire, pleasure to anger, reason to pain, and that all these elements are opposed to one another in the souls of bad men?

THEAETETUS: Certainly.

STRANGER: And yet they must all be akin?

THEAETETUS: Of course.

STRANGER: Then we shall be right in calling vice a discord and disease of the soul?

THEAETETUS: Most true.

STRANGER: And when things having motion, and aiming at an appointed mark, continually miss their aim and glance aside, shall we say that this is the effect of symmetry among them, or of the want of symmetry?

THEAETETUS: Clearly of the want of symmetry.

STRANGER: But surely we know that no soul is voluntarily ignorant of anything?

THEAETETUS: Certainly not.

STRANGER: And what is ignorance but the aberration of a mind which is bent on truth, and in which the process of understanding is perverted?

THEAETETUS: True.

STRANGER: Then we are to regard an unintelligent soul as deformed and devoid of symmetry?

THEAETETUS: Very true.

STRANGER: Then there are these two kinds of evil in the soul--the one which is generally called vice, and is obviously a disease of the soul...

THEAETETUS: Yes.

STRANGER: And there is the other, which they call ignorance, and which, because existing only in the soul, they will not allow to be vice.

THEAETETUS: I certainly admit what I at first disputed--that there are two kinds of vice in the soul, and that we ought to consider cowardice, intemperance, and injustice to be alike forms of disease in the soul, and ignorance, of which there are all sorts of varieties, to be deformity.

STRANGER: And in the case of the body are there not two arts which have to do with the two bodily states?

THEAETETUS: What are they?

STRANGER: There is gymnastic, which has to do with deformity, and medicine, which has to do with disease.

THEAETETUS: True.

STRANGER: And where there is insolence and injustice and cowardice, is not chastis.e.m.e.nt the art which is most required?

THEAETETUS: That certainly appears to be the opinion of mankind.

STRANGER: Again, of the various kinds of ignorance, may not instruction be rightly said to be the remedy?

THEAETETUS: True.

STRANGER: And of the art of instruction, shall we say that there is one or many kinds? At any rate there are two princ.i.p.al ones. Think.

THEAETETUS: I will.

STRANGER: I believe that I can see how we shall soonest arrive at the answer to this question.

THEAETETUS: How?

STRANGER: If we can discover a line which divides ignorance into two halves. For a division of ignorance into two parts will certainly imply that the art of instruction is also twofold, answering to the two divisions of ignorance.

THEAETETUS: Well, and do you see what you are looking for?

STRANGER: I do seem to myself to see one very large and bad sort of ignorance which is quite separate, and may be weighed in the scale against all other sorts of ignorance put together.

THEAETETUS: What is it?