In any of the above models, the specified truth is interpreted differently (it has a different meaning).

The theory underlines thus, that the model which generated a truth needs to be specified and accepted before the presentation of the truth. This basic requirement is always met in positive sciences.

In common life, the declaration of the model is not always done, and often the model does not even exist in an elaborate and coherent form. Emerging from here a long line of conflicts between individuals, groups or cultural zones, which all have their own reality a.s.sociated to the same external reality. This can be interpreted as a design deficiency of the brain. Some can compensate this hardware deficiency by software, e.g. the individuals situated on level 3 of consciousness (see the general theory).

There is a fairly common situation in external reality when a person states a truth, and then builds the model to support it. This happens usually for persons based on image models only, and when they interact with external reality, they only translate the image truth to a symbolic truth. Such persons are recognisable by their rudimentary logic and their tendency to fragment any discussion to particular sections of the external reality. Such persons can't discuss a single general subject.

Exercise: Verify yourself and others on the existence and status of the model, which generated any stated truth.

It is known from the general theory that a basic problem in the construction of a model a.s.sociated to the external reality is that we do not know beforehand the elements of the specific external reality. These elements need to be discovered, and the discovered elements are the only ones we can operate with.

Warning: The external reality, as defined in MDT, can't have elements and relationships. The elements and relations appear only in the model a.s.sociated to the external reality. However, in many statements we will use notions like elements and relationships of the external reality, but these need to be understood as elements and relations of the model a.s.sociated to the external reality. For the external reality, one can use the term 'ent.i.ty', which identified by the model will become an element of it. However, we have no word available to a.s.sociate to external reality in the case of relations. By perfectioning the language, such deficiencies will be solved.

A basic requirement for the existence of communication is the existence of a single common model accepted by both parts who want to communicate. Without a common symbolic model, there is no communication, as both sides will have their own list of definition of the terms a.s.sociated to the words.

Usually, communication is done only on symbolic models. However, there are more primitive forms of communication using image models (between people, between humans and animals, between animals).

The reality is defined in the general theory as the sum of all truths generated, or possibly generated, by a model. As each person has his/her own collection of models, the reality as understood by each person is different from one person to another.

It is important to specify that in the domain of positive sciences, fundamental models generally accepted do exist. One of these models is e.g. Newton's Mechanics. As this model generates a reality, all physicists consider that the 'reality' is the one generated by Newton's Mechanics, within its limits of applicability.

Due to reasons a.s.sociated to confusions of the science of knowledge, the reality generated by Newton's model is considered as 'objective'. Thus, "objective reality" is a term generated by a generally accepted model in specified conditions. From this point of view, the fact that the Sun revolves around the Earth is an "objective truth", at least at the level of the year 1500.

It needs to be stated by all means that without a model, the external reality cannot be perceived. After building a model a.s.sociated to the external reality, what we perceive is what the model states as perception. If, e.g. we say that 'snow is white', this is the result generated by a model a.s.sociated with external reality, external reality which contains the element 'snow'. One of the properties of the element 'snow' is that it is white. Under the microscope (another model) the same snow looks transparent.

As we already mentioned, reality is the one generated by the model a.s.sociated to a given external reality. Each time we state a truth, we have to specify first the model.

Example: There are an A and a B person. A is taller than B, as it results from measurement. The term 'length' is generated of the model 's.p.a.ce', as Euclid's Geometry and Newton's Mechanics understand it. These fundamental models characterize this truth as objective. If we say that "A is more attractive than B", this is a subjective truth. However a model has also generated this truth, more or less elaborate/ specified and more or less accepted by different persons.

The conclusion is that the term 'subjective truth' is resulting from a model, which is not unanimously accepted or insufficiently elaborated. In this case, it is clear that people should avoid such truths or should declare the model.

With the evolution of thinking, the term 'subjective truth' will be removed from the thinking system.

ETA 3: Fundamental problems a.s.sociated to scientific knowledge

Computers are known as devices used to play complex games based on intelligence, to write texts of different types, to make calculations, to store and manage data, to send or receive information, to build and operate symbolic models, etc.

A question occurs however: which is the principle of work of a computer?

If we do not interact with the computer via a primary programming language (a.s.sembler or machine language), I believe that it is impossible to find the principle of work of the computer either from in- or outside of it.

The fundamental function of a computer is to do logical and arithmetical operations with binary numbers with the help of an electronic device (register) called 'acc.u.mulator'.

If we are in a text editor, for instance, and we press a key corresponding to a letter, that letter will show on the screen. For the unaware, it is difficult to imagine that by pressing a key a.s.sociated with a letter, a register-acc.u.mulator will make hundreds or thousands of logical and arithmetical operations on binary numbers, only to have that letter shown on the screen.

This example wants to ill.u.s.trate that, based on the external a.n.a.lysis of what is happening, it is impossible to figure out the principle of work of a ridiculously simple device as a computer (ridiculously simple compared to the brain of a dog, e.g.)

The method used in positive sciences is not the a.n.a.lysis of primary data. The method of a.n.a.lysis works on extremely simple systems, which can be perceived on image models as well. The method used in positive sciences is to guess a symbolic model, based more or less on the interaction with external reality, and to verify the model.

It results that the method of understanding the brain based on the a.n.a.lysis of primary data is at least inefficient.

A fundamental problem of knowledge is that primary facts can be understood only if a model to integrate them already exists. Without a model, we are forced to build one on the spot. Thus, each fact of the external reality could be understood based on a local model. The correlation between facts, each understood in its local model is impossible. This is why a method of guessing a fundamental model was imposed. Based on the single fundamental model the facts are interpreted and reinterpreted. Such a method allows the correlation of the primary facts.

If the model does not make good predictions, it will be modified and the process restarted from scratch, until we find the model in which all the primary facts can be understood. The process stops when the predictions are true with an acceptable rate. In that phase we can talk about knowledge.

As a comment, we need to say that the a.n.a.lytical method is based on short- range models (can be affected by schizophrenia and XSPC), while the synthetic method is based on long-range models which allow not only correlation between facts, but also a cross-check between the local models.

The need for a single fundamental model comes from the fact that any used word needs to have a unique definition. This is true only in case of the existence of a single fundamental model.

Example: what would happen if in common language everybody used different definitions for the words used? The communication would not exist, everyone talking his/her own language.

The conclusion is that any positive science is based on a single fundamental model, stated from the very start. This symbolic model can be based on primary facts, results of the interaction with external reality or on theoretical principles (e.g. the principle of inertia in Newton's Mechanics cannot be visibly connected by facts seen in the external reality).

However, as in the external reality there are a huge number of facts difficult to correlate, the method to find the fundamental symbolic model is guessing. Once the model built, this will order in a univoque manner all the primary facts. Moreover, it will make predictions that will lead to new discoveries or confirmations of itself.

As we have shown in the general theory, we reflect sections of the external reality in models. The models make predictions. If the predictions are good, we will use the model a next time too, as it proved to be useful.

Now we have the normal answer to a fundamental question asked for long time: 'why do the laws of nature exist?' or 'Why the world has an order?'

As it results from MDT, we reflect the external reality based on symbolic models. These symbolic models need to be logical in order to be stable. If a symbolic model a.s.sociated to external reality will not reflect it correctly, we will build a new model.

Example: The external reality can change due to the movement of some objects. Then we will build a symbolic model containing the term 'velocity'. This symbolic model will make good predictions provided the objects move at a constant velocity. If the velocity is not constant, the model will not reflect correctly the external reality. Then we will build a new symbolic model, introducing a new element called 'acceleration'. This model will make correct prediction for the objects that move at variable velocities as well. Thus, by building of adequate models, the external reality is reflected by stable models.

It is very easy to confuse the external reality with its 'image' generated by a stable symbolic model.

As we know, we have no direct acces to external reality. We perceive it based on some a.s.sociated models. Thus, as a conclusion, the impresion that nature is a structure based on stable laws and order comes from the fact that we reflect the external reality based on logical and stable symbolic models.

ETA 4: General Communication Language (GCL), dictionary

GCL is the first symbolic model generated by the human brain. At the beginning, only its spoken form existed, later it appeared as a written language too.

As the purpose of the construction of models is to predict the evolution of external reality, GCL was always a.s.sociated directly or indirectly with external reality.

GCL is a very special symbolic model. It is used both for general communication and for building other more precise symbolic models.

Examples of developed languages included in GCL: diplomatic language, juridic language, logical and mathematical language, languages based on gestures and signs, computer languages.

GCL can be used to build symbolic models that are a.s.sociated to external reality, e.g. the positive sciences.

It is supposed that GCL occurs by spontaneous interaction between people but this is an abnormal mode of occurence. It is not clear to me that a language can start from scratch, but let's suppose so. The abnormal mode of occurence is a.s.sociated with another aspect. The language for any device used to process information (as the brain is) is made of a collection of terms and relations. Any element/relation of the symbolic model (language) must be a.s.sociated with a component/function of the hardware. That is, the hardware must be known before the language is built. This is the normal situation, e.g. when a computer, which has no a.s.sociated programs, has to be used.

But, as it is believed, the language used by the brain appeared without knowing the hardware. The main consequence is that all the words, which have to be a.s.sociated with the basic feature of the hardware, have no precise definition.

Thus, we find in dictionaries what I call "external definition" of the words.

That is, such definitions are not based on the hardware. MDT as a theory a.s.sociated with the hardware, generates "internal definitions" of the words.

Some such definitions will be given below.

Dictionary of internal definitions for some words:

1. To believe: there is an incomplete (unstable) model. Such a model could become stable (harmonic/logic) if some artificial elements/relations are included (artificial means that something is not generated by the interaction with the external reality). After such changes, the model becomes stable. Any truth generated by such a model must be a.s.sociated with the word "to believe". Also, the artificial changes must be specified before.