Page:Popular Science Monthly Volume 22.djvu/787

Rh categories of mental faculties. Anæmia is likewise a condition of frequent occurrence. At later periods, as Luys says, the optic thalami are the seats of degenerations which show that there have been frequent perturbations of the circulation. He is very strong in his conviction that there are secondary changes, which are the cause of the transformation of psycho-sensorial hallucinations into those which Baillarger designated psychic. In my opinion, they are the cause of the hallucination becoming a delusion, and, indeed, between a psychic hallucination and a delusion there is very little difference. The former can not exist without the involvement of the intellect.



BELGIAN philosopher, M. Stas, declared, two years ago, that "no science to which measure, weight, and calculation are not applicable can be considered an exact science; it is only a mass of unconnected observations, or of simple mental conceptions." I agree to this without reserve. Undoubtedly, vain imaginations and crude theories, which have form without solidity, should be banished from science; but it does not follow that we must define science as a collection of weights and measures, and calculations upon them, or as consisting of combinations of algebraic formulas from which other formulas may be deduced. These matters of weight, measure, and calculation must have some synthesis or useful purpose in view. They should throw light upon some law, and that a law which is an idea, or which is susceptible of being converted into an idea. It is the philosophic thought penetrating them that gives interest to the statistical labors of Quetelet. The cry of the positivists of the day is for "facts!" To that I oppose another cry: "Ideas! give us ideas!" A fact without an idea is a body without a soul, a useless incumbrance to the memory. I come to the defense of speculation. While I view with impatience volumes of figures, operations, and formulas, of which the signification and bearing can not be perceived, I am inclined to be grateful to the man who throws out a new idea, though it be a thousand times false. There is always more to be learned from the thinker who talks nonsense logically than from the observer who does not reason at all. From nothing, nothing can come, but error may bring forth the truth at the price of its own death.

Laying aside these generalities, let us consider an example of the 