sions. The adherents of such a process are glad to certify the value of a first thought. Conscientious workers, who are shy at bringing their thoughts before the public until they have tested them in all directions, solved all doubts, and have firmly established the proof; these are at a decided disadvantage. To settle the present kind of questions of priority only by the date of their first publication, and without considering the ripeness of the research, has seriously favored this mischief.
"In the type-case of the printer all the wisdom of the world is contained which has been or can be discovered; it is only requisite to know how the letters are to be arranged. So, also, in the hundreds of books and pamphlets which are every year published about ether, the structure of atoms, the theory of perception, as well as on the nature of the asthenic fever and carcinoma, all the most refined shades of possible hypotheses are exhausted, and among these there must necessarily be many fragments of the correct theory. But who knows how to find them?
"I insist upon this in order to make clear to you that all this literature, of untried and unconfirmed hypotheses, has no value in the progress of science. On the contrary, the few sound ideas which they may contain are concealed by the rubbish of the rest; and one who wants to publish something really new—facts sees—himself open to the danger of countless claims of priority unless he is prepared to waste time and power in reading beforehand a quantity of absolutely useless books, and to destroy his reader's patience by a multitude of useless quotations."[1]
In order to give a psychological illustration, I will refer to the case of mediate association of ideas.[2] The existence of such associations was discovered in the course of an extended experimental investigation of the manner in which ideas were associated. It was proved, for the first time, that such associations are made. A single personal observation of this sort is to be found in Hamilton's works. A still earlier one is reported from Hume, and a favorable perusal of the works of Aristotle would probably reveal something similar. Such cursory observations, fruitless and unconfirmed, do not entitle the makers to any special credit. The credit of an experimental discovery remains with the discoverer, regardless of previous guesses that may have hit the truth.
The debt of the new psychology to the old psychology of the past does not involve any claims by the "sensation-psychology" of the present. Among the pupils of the old psychology there
