Page:Principles of Psychology (1890) v1.djvu/213

THE METHODS AND SNARES OF PSYCHOLOGY. 193 must submit to a regular siege, in which minute advantages gained night and day by the forces that hem her in must sum themselves up at last into her overthrow. There is little of the grand style about these new prism, pendulum, and chronograph-philosophers. They mean business, not chivalry. What generous divination, and that superiority in virtue which was thought by Cicero to give a man the best insight into nature, have failed to do, their spying and scraping, their deadly tenacity and almost diabolic cunning, will doubtless some day bring about. No general description of the methods of experimental psychology would be instructive to one unfamiliar with the instances of their application, so we will waste no words upon the attempt. The principal fields of experimentation so far have been : 1) the connection of conscious states with their physical conditions, including the whole of brain- physiology, and the recent minutely cultivated physiology of the sense-organs, together with what is technically known as 'psycho-physics,' or the laws of correlation between sensations and the outward stimuli by which they are aroused ; 2) the analysis of space-perception into its sensa- tional elements ; 3) the measurement of the duration of the simplest mental processes ; 4) that of the accuracy of re- production in the memory of sensible experiences and of intervals of space and time ; 5) that of the manner in which simple mental states influence each other, call each other up, or inhibit each other's reproduction ; 6) that of the number of facts which consciousness can simultaneously discern ; finally, 7) that of the elementary laws of obli- vescence and retention. It must be said that in some of these fields the results have as yet borne little theoretic fruit commensurate with the great labor expended in their acquisition. But facts are facts, and if we only get enough of them they are sure to combine. New ground will from year to year be broken, and theoretic results will grow. Meanwhile the experimental method has quite changed the face of the science so far as the latter is a record of mere work done. The comparative method, finally, supplements the intro-