Epistemology. The classical, semantic and coherent conceptions of truth
Epistemology, as it was said in chapter 1, is the theory of cognition and regards problems of knowledge, knowability, truth, interconnection of subject and object in the process of cognition and so forth. The central problem of the epistemology is the problem of truth that is what the truth is, how itís possible etc.
ďWhat is the truth?Ē ─ asked Pilate in Johnís gospel. Many approaches are possible but the most natural and intuitively clear for us probably will be the classical (correspondent) conception of truth, according to which truth is the knowledge corresponding to reality. What opinion on the problem of truth can be more natural than this one? Nevertheless, in spite of all its clearness and simplicity the classical conception leads to some problems. They are the following:
1. The problem of the cognized reality nature.
It consists in that all our ideas of reality, all sensual data and thoughts are part of our consciousness, out of which we cannot get out. It can be illustrated with the next mental experiment. Let us imagine a brain in a test-tube. Itís placed in the physiological solution and electrodes, through which the agitating electric impulses are given, are attached to it so that it gets an illusion of some outer reality (that it isnít merely the brain but a human who lives a sanguineous life, commits exploits, falls in love and so on) with no suspicion that in real itís only the brain in the tube. Do some modes to discover the real state of affairs exist for the brain? Do they exist for us? Maybe we also are only some sort of a brain in a beaker, as it was shown in the film ďThe MatrixĒ. We canít answer this question, because we canít get out beyond our consciousness. This is the inner (letís call it metaphysical) level of the problem.
The outer (letís call it epistemological) one consists in, that we look at the outer world around us not directly but through the prism of our previous knowledge. We cannot get out beyond our theoretic representations and interpretations and look at things as they exist by their own. The latter is reflected in the so-called Kuhn-Feurabend thesis:
n facts are formulated in the language of some theories;
n the competing theories have different, incompatible with each other languages;
n whence there are no facts, on the base of which the rational choice in favor of one of these theories can be made.
2. The problem of the correspondence character.
The correspondence character is not always clear and obvious. For example, what do the complex numbers (i=V─1) and the expressed by them physic values correspond to? The example of such value can be the formula for the complete electric resistance or impedance (Z=R+iL), which consists of the real R and the imaginary L parts. We observe only the real part and do not the imaginary one. The latter points to the future values of resistance. But the principle of correspondence remains unclear.
A Swiss psychoanalyst K. G. Yung suggested to represent the correlation of the conscious and unconscious by analogy with the impedance, i. e. the reality is R=O+iS, where O is the objective and S ─ the subjective components of reality. The correspondence of knowledge to reality presupposes the correspondence of the subjective (knowledge) to the objective (reality). But what does the knowledge of the subjective constituent correspond to?
3. The problem of truthís criterion.
Any knowledge requires a criterion of its verity. The criterion, being itself knowledge, requires a criterion of its own verity (the second criterion). The second criterion needs the third, the third ─ the fourth and so on, to infinity. We get an infinite succession of the truth criteria. This is in theory, in practice this regression is broken somewhere with a volitional impulse but the problem of criterion remains. The break means the stopping of argumentation and replacement of it with a belief but the true knowledge cannot be grounded on the only belief.
4. The problem of paradoxes.
Let us regard the follow statement: ďA village barber shaves all men in the village except those, who shave themselvesĒ. The question is ďWho shaves the barber?ĒIf we answer Ďthe barber himselfí, it contradicts to the clause Ďexcept those, who shave themselvesí. If we say Ďsomebody elseí, it also contradicts, this time to Ďa barber shaves all men, except those, who shave themselvesí. This is a paradox with no correct answer. Another example of similar paradoxes is ďIím telling liesĒ. Is it the truth (then Iím really telling lies, that means it canít be truth) or false (then Iím not telling lies but telling truth)? The cause of this last paradox consists in turning the context of statement on the statement itself (look above the representation of the subjective and objective components of reality by Jung). That means the different types of things (the context of the statement and that, itís directed on, in the first case; those, who shave others, and those, who donít, in the second case) are mixed together, where the paradoxes come from.
In order to avoid paradoxes itís necessary to divide distinctly these different types, especially ─ the context and that, itís directed on. If we do it, we shall get the next definition of truth. ďíPí is true if and only if itís really PĒ. This is the so-called semantic definition of truth, which is the specified version of the classical one. In it the context of statement and its reference domain are distinctly separated from each other.
As the means of solving the problem of truthís criteria the coherent and pragmatist conceptions of truth can be used.
The coherent conception asserts that truth is the coherent and non-contradictory knowledge. This conception should work especially well in mathematics and the formal sciences on the whole. As a particular criterion of verity itís also applicable to the empirical sciences (if to introduce the knowledge of facts into the frame of the coherent system). In order to be quite coherent the system of the empirical knowledge must include absolutely all possible facts knowledge. It must also include mathematics. But what about mathematics, in 1931 K. Goedel the German mathematician proved his famous theorems asserting that the coherency of a formal system containing mathematics in canít be proved in limits of this system. That means the abilities of the coherent conception are limited even in the frame of mathematics.