Let us begin with the different theories of truth. We have so far discussed in the previous post, the two types of knowledge based on the two types of statements accepted as the demarcation of knowledge in the sciences. Let us now consider different theories of truth. The main question that should be considered here is: “When does one claim that his/ her knowledge claim has the element of truth or falsity?” The answer to this question will be based on three familiar theories of truth: coherence, correspondence, and the pragmatic theory of truth.
The coherence theory of truth has to do with the well-formed formulas adopted in the field of the formal sciences like mathematics, logic, trigonometry, geometry or linguistic systems where definitions are considered as tautologies. These well-formed formulas (WFF), have been accepted as universal and have been proven to be true within the assumptions or axioms of the system where they belong. For example, the elements of Euclidian geometry and the Pythagorean theorems have been accepted as a well-formed formula in the field of mathematics and geometry. Coherence deals with the consistency of the truth of statements being claimed within the system that is being used or employed. For example, one could show a certain proof by using an accepted or well-formed formula for a certain mathematical problem.
On the other hand, one could show the unacceptability or falsity of a certain statement if it could be shown that there are logical, mathematical or even definitional inconsistencies within the system that is being adopted. For instance, if a deductive Truth as coherently argument in logic does not follow the accepted logical form, then, the argument could everywhere be rejected as invalid. This is because it could be shown by.formal analysis (e.g. through a proof of validity or by virtue of a truth table) that has a false truth value based on its incorrect logical structure.
Another example is, if you would make a statement that: That which is blue is not colored. You would right away, by mere analysis of the definition of terms within the statement that it is false because the predicate colored is contained in the subject blue, which is an example of a color. In other words, the truth or falsity of the claim being made is already found in the linguistic system that is being used. Thus, coherence is a matter of consistency within the system and its well-formed formula, in the formal sciences. It is a matter of the faculty of reason to discover these inconsistencies and formal truths. The faculty of reason is the one responsible for the formal types of knowledge that we accept. It is, of course, assumed that man’s rationality is universal.
The correspondence theory of truth, on the other hand, has to do with the correspondence of knowledge claims being made with the state of affairs in the world. Different philosophers, depending on their philosophical inclinations, would have different interpretations of what this ‘state of affairs’ should be. For the sense data philosophers like Alfred Jules Ayer, the given in the world are sense data because material objects are logical constructions out of sense data. For the logical atomists like Bertrand Russell, espousing the referential theory of meaning, where he believed that the meaning of a word is its referent or the object denoted by it, assumes that there must be atomic facts made up of simple objects that correspond with elementary propositions made up of simple names. Suffice it to say that no matter what their versions or answers to what is given as the state of affairs in the word may be, correspondence theory assumes that there is something given outside, in the realm of sense experience that we perceive as an objective reality.
For example, when you claim that: ‘Harry is a bachelor,’ the truth of this statement could not be claimed solely by analyzing the key terms contained within the statement. One has to go outside of the statement and check whether the information being added about Harry is true. Thus, one has to verify the claim using data from the world of experience. Similarly, you have to check the state of affairs when you make the statement: ‘The dog is inside the doghouse,’ before claiming truth or falsity.
Thus, the correspondence theory of truth would have sense perception or experience as its source of knowledge. That is, our perceptions become the basis for verifying something as true or false about the world. This criterion of verification was emphasized by Alfred Jules Ayer, in his book entitled, Language, Truth and Logic (1936) where he defined clearly the limits of empirical statements as only those that are empirically verifiable through experience. If something is not empirically verifiable, then, they may be considered as meaningless utterances. Ayer, together with the other logical positivists, would propose the emotive theory of meaning for statements that will not pass this process of verification.
For Ayer, ethical concepts are pseudo concepts because they could not be subjected to the process of verification. Thus, they do not have cognitive meaning (something that is empirically verifiable about the world) but only emotive meaning, where your purpose is to express your feelings and emotions and to evince or evoke the same feelings and emotions from others. Unfortunately, the logical positivists, whether wittingly or unwittingly, unnecessarily narrowed down the realm of knowledge by rejecting a wide range of ethical, value, aesthetic, and even religious statements and concepts, which they considered to contain only emotive meaning. Hence, evaluate or normative ethical statements, for them, are cognitively meaningless because they do not contain any assertion that is verifiable.