It is very presumptuous and hazardous to essay a definition of truth, yet since such a definition is a great desideratum, and since it will not be effected except by earnest trial, and since also, in such a matter, even failures that are consequent on devoted attempts are instructive to subsequent attempts, we venture our submission:
A thought is true which while representing its applicate (that is whatever to which it is directly applied) also, in so far as its purport implies, represents in mind a thorough and respective parity and ratio, through which each thought-analyton and thought-syntheton (whether ground, mode, limit, number, part, relation, etc.) corresponds to its proper applicate-analyton or applicate-syntheton. Truth is this representative and correspondent parity and ratio in general. A thought may be true and yet incompetent, that is unfit to serve some assigned purpose or turn in view, by reason, it may be, of its irrelevancy, or it may be of its restricted application or purport. It is a question that has been much mooted whether or not our sensations are true to their mind-alternate excitants. The argument towards showing that they are would be prolix and must be passed. If however they are not true it would be interesting to hear by what quality or nature they are to be characterised in respect to their verity.
Attention is a mental activity of considerable importance in logic in connection with that very fruitful source of error, mal-observation. But by far the most important mental activity to be studied and thoroughly known for the behests of logic is Conception, with its all important adjunct of denomination. The verity or error of all other mental operations that generate thought depends largely on the truth or untruth, the competence or incompetence of Conception. On our conceptions as a basis is erected and must ever be erected every scheme of our notation, and in so far as our conceptions are untrue or incompetent, so probably is, and so will be, in perhaps a multiple measure, all our knowledge. Very much more ought to be said in this connection, but space will not permit.
The mental operation which is here called Recognition, but which has been called hypothesis and otherwise, and which the author reviewed calls Identification, has not received the attention from logicians in general which its importance requires. It is a true variety of inference, as Mr. C. S. Peirce has fully shown. Our conceptions which are the central facts of logic would be of little value to us were we not able truly to subsume our perceptions under them. A variety of facts are available to show how very often we do this wrongly, imperfectly, or not at all.
Induction, and its rationale, depends also very largely upon conception and its intimate consequences, denomination, attribution, and relationising. Deduction and the Syllogism are trite themes, although the part that attribution plays in the process has been insufficiently noticed, and although the rules of deduction from relation-terms, the most important and fruitful of all, are as yet very partially ascertained. What is needed as an indispensable prerequisite to this last, seems to be a census and classification of the manifold relations that are known, after the model of say Roget's Thesaurus, and then a determination of the consequences of such combinations and constructions as are admissible and fruitful, and a tabulation of the same as our multiplication table is a tabulation of the consequences of the multiplication of numbers. The Logic of Relatives as it is called suffers from its having been formed thus far on so very abstract and formal a plan that its formation lacks the check and correction of frequent comparison with concrete knowledge, while its results are almost if not quite useless owing to their extreme generality, which in defect of the mediate formula leaves them inapplicable to aught that can manifest their utility or power.
F. C. R.
THE TIME-RELATIONS OF MENTAL PHENOMENA. By Joseph Jastrow. New York:
N. D. C. Hodges.
The accomplished Professor of Psychology at the University of Wisconsin gives in this publication, which forms one of the series of "Facts and Theory Papers" issued by Mr. Hodges, the results of numerous observations by Cattell, Münsterberg and other observers. His object is to present a general view of what has been done already in this department of research. The study of the time-relations of mental phenomena is of importance in various connections. As Professor Jastrow remarks:
"It serves as an index of mental complexity, giving the sanction of objective demonstration to the results of subjective observation; it indicates a mode of analysis of the simpler mental acts, as well as the relation of these laboratory products to the processes of daily life; it demonstrates the close interrelation of psychological with physiological facts, an analysis of the former being indispensable to the right comprehension of the latter; it suggests means of lightening and shortening mental operations, and thus offers a mode of improving educational methods; and it promises in various directions to deepen and widen our knowledge of those processes by the complication and elaboration of which our mental life is so wonderfully built up."
The results of the observations referred to by Professor Jastrow are given in Tables of Simple Reaction Times and of Complex Reaction Times. One of the most important points considered is "the overlapping of mental processes," as to which Cattell made a special study. From the fact that the time needed for the performance of complete operations, as multiplying numbers and reciting a verse or two at the same time, is shorter than the sum of the times required to do each separately, it is inferred that the mind should be likened not "to a point at which but a single object can impinge at one time, but rather to a surface of variable extension." Moreover, "the performance of a complex and extended mental task is not the same thing as the separate performance of the several elements into which that task may be analysed." The addition of a classified Bibliography adds much to the value of Professor Jastrow's interesting little work.