detecting any unreality, that is, lack of insistency, in a notion. First, many ideas yield at once to a direct effort of the will. We call them fancies. Secondly, we can call in other witnesses, including ourselves under new conditions. Sometimes dialectic disputation will dispel an error. At any rate, it may be voted down so overwhelmingly as to convince even the person whom it affects. Thirdly, the last resort is prediction and experimentation. Note that these two are equally essential parts of this method, which Professor Pearson keeps—I had almost said sedulously—out of sight in his discussion of the rationality of nature. He only alludes to it when he comes to his transcendental 'pure suggestion.' Nothing is more notorious than that this method of prediction and experimentation has proved the master-key to science; and yet, in Chapter IV., Professor Pearson tries to persuade us that prediction is no part of science, which must only describe sense-impressions. [A sense-impression cannot be described.] He does not say that he would permit generalization of the facts. He ought not to do so, since generalization inevitably involves prediction.
The third leg of the argumentation is that human beings are so much alike that what one man perceives and infers another man will be likely to perceive and infer. This is a recognized weakness of the second of the above methods. It is by no means sufficient to destroy that method, but along with other defects it does render resort to the third method imperative. When I see Dr. Pearson passing over without notice the first and third of the only three possible ways of distinguishing whether the rationality of nature is real or not, and giving a lame excuse for reversing the verdict of the second, so that his decision seems to spring from antecedent predilection, I cannot recommend his procedure as affording such an exemplar of the logic of science as one might expect to find in a grammar of science.
An ignorant sailor on a desert island lights in some way upon the idea of the parallelogram of forces, and sets to work making experiments to see whether the actions of bodies conform to that formula. He finds that they do so, as nearly as he can observe, in many trials invariably. He wonders why inanimate things should thus conform to a widely general intellectual formula. Just then, a disciple of Professor Pearson lands on the island and the sailor asks him what he thinks about it. "It is very simple," says the disciple, "you see you made the formula and then you projected it into the phenomena." Sailor: What are the phenomena? Pearsonist: The motions of the stones you experimented with. Sailor: But I could not tell until afterward whether the stones had acted according to the rule or not. Pearsonist: That makes no difference. You made the rule by looking at some stones, and all stones are alike. Sailor: But those I used were very unlike, and I want to know what made them all move exactly according to one rule. Pear-
