Other Views on Laws of Thought.
In other schools of philosophy, very various accounts are given as to the nature and origin of these laws. It seems well to notice here three theories differing widely from that set forth in the preceding sections. These views respectively regard the laws of thought
(1) as subjective laws of the understanding, of whose objective, validity, however, we can have no rational guarantee,
(2) as principles determining the growth of that 'ex perience,' which men erroneously distinguish into thought on the one hand, and things on the other hand,
(3) as mere generalizations from experience.
The first view is that of Kant. Among English logicians it is explicitly taught by Mansel. He tells us that the principles of thought are "laws under which the mind is compelled to think, and which it cannot transgress, otherwise than negatively by ceasing to think at all."
"It may be," he adds, "that the conditions of possible thought correspond to conditions of possible being, that what is to us inconceivable is in itself non-existent. But of this, from the nature of the case, it is impossible to have any evidence" (Proleg. Logica, 7r, 72).
It is needless to point out that such a view as this leads directly to philosophic scepticism.
The second view is represented by Mr. Bosanquet. We have already called attention to the theory held by the neo-Hegelian school of logicians, according to which the operations of the mind are vital functions by which the so-called 'real' world has been constituted.
It is under this aspect Mr. Bradley regards the laws of thought. He holds that we cannot say that these principles are merely laws of thought, if by that we mean thought as distinguished from things: "Since a separation between intelligence and experience is purely fictitious, there is nothing to be gained by cutting down the content of these principles to a minimum in the hope of restricting their reference to thought as opposed to things."
They are "the animating principles of growth" which govern the development of experience: and if we recognize them as "postulates of know ledge," this is because "on analysis of experience, they are found to be active factors in it from the first" (Logic, II. 205— 207).
Mill (Logic, I., p. 308. Exam. of Hamilton, p. 417) explicitly repudiates the view that these principles are subjective laws of the thinking faculty. He holds that they are conclusions derived from a constant experience of their truth. We have never as a matter of fact known any case where two contradictories have been simultaneously true.
Hence we rightly lay down a general but empirically discovered principle to that effect. As for the law of Excluded Middle, we have already seen that he holds that it needs qualification before it can be admitted as universally true.
It must, he admits, be owned that "we cannot now conceive the opposite of these laws to be true. But this inconceivability is of little value as a criterion of truth to those who know how artificial, modifiable, the creatures of circumstances and alterable by circumstances, most of the supposed necessities of thought are."
Constant experience of one character is, in his view, sufficient to lead us to regard its opposite as inconceivable.Return to Logic Contents Page Return to Philosophy Home Page