Abstract

The debate about the criterion of truth has always been closely linked with the battle lines of philosophy. Philosophers of different philosophical lines use different criteria of truth, each of which is consistent with the criterion of truth common to its philosophical line. Idealist philosophies advocate the primacy of thinking [, implying more the structure or process of thought, as compared to "thought" , implying a more or less coherent idea, viewpoint, or system, the result of thinking - Tr.] and regard the material world as secondary, believing that human thought and truth are dropped from heaven, or are generated by the subjective consciousness itself. The idealist criterion of truth is sought in thought itself. Idealist philosophers cannot use the criterion of practice because the entire theory of idealism, including its view of truth, is made up wholly of subjective and empty constructs which would not pass the test of practice. If idealist philosophy used the criterion of practice it would undoubtedly refute itself. Only the materialist philosophical line is linked by its very nature with the criterion of practice. Materialism affirms the primacy of the material world, and the secondary nature of thinking as a reflection of the material world, regarding truth as a correct or accurate reflection of objective things. To test whether or not such a reflection is correct, it is not permissible to appeal to thought itself; we must rely on social practice. To discuss the truth of thinking, separate from social practice, would be to abandon materialism and fall into idealism. Therefore we say that the materialist philosophical line, as part of its basic fundamental nature, embraces the acceptance of the criterion of practice, or we say that it is fundamentally linked to the criterion of practice. Of course, to say that the materialist philosophical line is fundamentally linked to the criterion of practice is not to say that every materialist is able to consciously adopt the criterion of practice, rather that materialism ought to use social practice as the criterion of truth. Only in this way can one maintain a thoroughgoing materialism. However, ought to is one thing, while reality is quite another. In reality, the materialists coming before Marx did not self-consciously adopt the criterion of practice, but for the most part used subjective criteria. For example, the well-known materialist [Ludwig] Feuerbach [1804-18721 thought that "agreement of the majority" or "common opinion" was a criterion of truth. "Agreement" and "opinion" are subjective, and such a theory of the criterion of truth stands in contradiction to the materialist line that Feuerbach advocated. With a criterion of that sort, not only would it be impossible to validate the objective truth that Feuerbach sought; on the contrary, one could refute objective truth totally, refute the materialist line. Since subjective criteria of truth solve the problem of truth within the subjective realm and must refute the objective nature of truth, subjective criteria of truth are therefore fundamentally incompatible with the materialist line of thought. Only the criterion of practice accepts objective truth, and is compatible with the materialist line of thought. That materialists before Marx were unable to self-consciously employ the criterion of practice and used subjective criteria of truth reveals the limited and partial nature of materialism. By introducing social practice into the theory of knowledge and by determining that practice is the criterion of truth, thereby overcoming the limitations and incompleteness of the old materialism, Marxism developed the materialist theory of knowledge into a completely scientific theory. This was an enormous contribution to the history of philosophy. However, the acceptance or rejection of the criterion of practice is not a minor problem, but rather a major problem that affects all philosophical lines of thought. To uphold the criterion of practice is to stand on the side of materialism. On the other hand, to use the criterion of thought to refute the criterion of practice is to fall into idealism