FREGE'S ANTI-PSYCHOLOGISM AND ITS RELATION TO THE SUBJECT MATTER OF LOGIC

Psychologism, which emerged in the late eighteenth century, claims that all products of the human mind arise according to the laws of psychology. For this reason, it accepts that all philosophical or scientific concepts and problems can be explained according to subjective psychological experiences or common elements formed from what is observed in all men. The acceptance of this approach will cause us to understand all sciences as sub-branches of psychology, or at least cause no scientific claims that have not been approved by psychology to be taken seriously.There are various psychologistic approaches. Some of them make a definition of logic based only on the individual; some are based on logical behavior observed in all humans; some explain based on a mental faculty that they claim to exist in all humans; others try to make a definition of logic on the basis of an ideal cognizer who always makes logically perfect decisions. Three of them are understandings that are unlikely to escape relativism. The idea of mental faculty, on the other hand, has problems in explaining false. Because it remains unclear how people can do false claims despite a built-in faculty. Since every person makes decisions according to a built-in faculty in the decision-making process, the decision taken must be true. If false claims are also possible, the question of according to what and when does this faculty work or not? appears to be a valid one.Frege noticed the problems caused by psychologism, which emerged in the century he lived, in the field of philosophy and logic, and he became one of the leading thinkers who strongly opposed this view. As far as we can determine, according to him, there are two main problems with psychologistic approaches. First of all, it is not possible to deal with and explain the concept of true, which falls under the field of logic, in an appropriate way, in terms of psychology. Because true is not in a different position for psychology than for other sciences. Secondly, it is not possible for psychology to be normative in terms of starting from the mental processes of individuals and to determine laws that are valid in general. Because psychological motives are the cause of false claims as well as true claims, and since psychology is subjective, it is not possible to deduce a norm based on its data.Frege begins his investigation by asking what true is. Although he thinks that true is indefinable, he thinks that we can at least determine how true can be used appropriately based on everyday usages of true. The everyday use of true gives us four starting points to question. The first is objects that are representations of things, such as a picture or painting; the second is the ideas as the representations of these pictures in our minds; the third is the sentences we have built about these pictures, ideas, or the relations between them, and the fourth is the thoughts that are the meaning of these sentences. The first two of these make it necessary to assume a correspondence relation between the pictures and the objects they represent or the ideas and what they represent. However, when this correspondence is tried to be explained, we will encounter a new correspondence relation, and thus it will be inevitable to fall into infinite regress. If the truth of the sentences does not mean the truth of the sound sequences, which would be absurd, the truth of their meanings is at the stake. The meanings of sentences are thoughts. Of the four identified, then, only thoughts are worthy of the proper use of true. In this case, what the logician should investigate should be the laws of the truth of thoughts.Frege says that if someone doesn't understand truth, I can't explain truth in any other term. I cannot talk about primitive terms and develop some sense of truth. Consequently, we must accept truth as something primitive and simple, which we either apprehend or fail to apprehend.Frege tries to purify logic and mathematics from ideas, which are individual perceptions, and therefore from the subjective. This effort is also the main motivation for his attempts to express logic in a formal language. Because it is extremely difficult for him to make logic by completely getting rid of the psychological connotations of everyday language. If this is not achieved, the invasion of logic by concepts related to human processes, mental images, etc., and confusion between the process by which we obtain an understanding of meaning and what constitutes such understanding will be inevitable.Frege thought that by determining the appropriate usage of the word true, the above-mentioned goal could be achieved. Because it is a quality that is valid only for our thoughts. The subject of logic is precisely this quality. What makes all the subjects dealt with in logic the subject of a single science is that they serve to reveal the truth. However, psychology's relationship with truth is not such a relationship. What true means to physics or chemistry is like what it means to psychology. Since psychology, like other sciences, must put forward various propositions, when the truth of these propositions is in question, it will not be possible to explain their truth within psychology. It is clear that Frege's critiques pose problems for Frege in that they are on a Platonic basis, raise questions that every Platonic explanation raises, and require consistent answers to them. However, it is also clear that the problems that Frege's argument answers are also problems that all psychologistic understandings must resolve. However, it should not be overlooked that the psychologism that Frege opposes is primarily psychology that examines the beings that can only be accessed with insight through empirical methods, and it should not be forgotten that this type of psychology approach is not as popular today as it was in his time. The fact that this was overlooked, and the word psychologism remained at the center of the criticism of the great names in the history of philosophy has always caused this word to have bad connotations. For this reason, calling any philosopher a psychologist has been understood as a major criticism of him. However, Jacquette says that the efforts of some logicians, such as Rescher, and Quine, can be seen as an attempt at what he calls good psychologism. By following him, we must admit that an attitude that excludes all kinds of psychological considerations in philosophy or logic will be destructive and at least as wrong as sharp psychologism.