Validity of ideas

In the objective worth of our ideas there remains the problem of the validity. As all cognition is by ideas, it is obvious that the question of the validity of our ideas in this broad sense is that of the truth of our knowledge as a whole. Otherwise to dispute this is to take up the position of skepticism. This has often been pointed out as a means intellectual suicide. Any chain of reasoning (common sense) by which it is attempted to demonstrate the falsity of our ideas has to employ the very concept of ideas itself. Then insofar as it demands assent to the conclusion, it implies belief in the validity of all the ideas employed in the premises of the argument.

To assent the fundamental mathematical and logical axioms, including that of the principle of contradiction, implies admission of the truth of the ideas expressed in these principles. With respect to the objective worth of ideas, as involved in perception generally, the question raised is that of the existence of an independent material world comprising other human beings. The idealism of David Hume and John Stuart Mill would lead logically to solipsism (the denial of any others besides ourselves). The main foundation of all idealism and skepticism is the assumption (explicit or implicit), that the mind can never know what is outside of itself. This is to say that an idea as a cognition can never go outside of itself. This can be further expressed as we can never reach to and mentally apprehend anything outside of anything of what is actually a present state of our own consciousness.

First, this is based on a prior assumption for which no real proof is or can be given

Second, it is not only not self-evident, but directly contrary to what our mind affirms to be our direct intellectual experience.

What is possible for a human mind to apprehend cannot be laid down beforehand. It must be ascertained by careful observations and by study of the process of cognition. This postulates that the mind cannot apprehend or cognize any reality existing outside of itself and is not only a self-evident proposition, it is directly contrary to what such observation and the testimony of mankind affirms to be our actual intellectual experience.

John Stuart Mill and most extreme idealists have to admit the validity of memory and expectation. This is to say that in every act of memory or expectation which refers to any experience outside the present instant, our cognition is transcending the present modifications of the mind and judging about reality beyond and distinct from the present states of consciousness. Considering the question as specially concerned with universal concepts, only the theory of moderate realism adopted by Aristotle and Saint Thomas can claim to guarantee objective value to our ideas. According to the nominalist and conceptualist theories there is no true correlate in rerum naturâ corresponding to the universal term.

Mathematics, astronomy, physics, chemistry, and the rest claim that their universal propositions are true and deal with realities. It is involved in the very notion of science that the physical laws formulated by the mind do mirror the working of agents in the external universe. The general terms of these sciences and the ideas which they signify have objective correlatives in the common natures and essences of the objects with which these sciences deal. Otherwise these general statements are unreal and each science is nothing more than a consistently arranged system of barren propositions deduced from empty arbitrary definitions. These postulates then have no more genuine objective value than any other coherently devised scheme of artificial symbols standing for imaginary beings. However the fruitfulness of science and the constant verifications of its predictions are incompatible with such a hypothesis.