Page:Popular Science Monthly Volume 13.djvu/343

Rh although it is relative to the human faculties. The revision of human testimony that physiological science now requires, and is qualified to undertake, is radical and revolutionary, but it is not suicidal; it is discriminating, not sweeping; not destructive, but constructive.

The demand is not for the rejection but for the reconstruction of human testimony; and the spirit with which this should be undertaken is not skeptical, but scientific.

This reform of logic, like all revolutions in science, should advance under the guidance of the scientific method. By the scientific method, I mean that method of obtaining and organizing knowledge which consists in defining, so far as is possible to expert human faculties, the boundaries between the possible and the probable, between the known and the unknown.

The scientific method can only be successfully used by those who are endowed with, or by discipline have acquired, what I am accustomed to call the scientific sense, by which phrase I mean the power of seeking truth through the intellect alone, uninfluenced by the emotions. For the tendency of truth, the scientific sense has no hopes and no fears, except so far as it may help to find the truth.

The scientific method is a part of the evolution of culture, of science, and of civilization; to absolute savagery everything is absolutely known; all natural phenomena are pronounced supernatural; with the beginning of knowledge there is a recognition of ignorance, which, in time, gradually subdivides so as to include all phenomena that can be brought to the attention of the human mind in one of these four grand divisions—the possible, the probable, the known, and the unknown. The constant effect and sign of progress in knowledge is the narrowing of the area of the known and the probable, and the extension of the areas of the unknown and the possible.

I. The corner-stone of the reconstructed edifice of the principles of evidence must be the recognition of the necessity of the testimony only of experts in all matters of science, and consequent absolute rejection of all testimony of non-experts, without reference to their number or the unanimity of their testimony.

A few definitions are here needed:

Science is systematized knowledge.

An expert is one who can see all sides of a subject.

A non-expert is one who sees but one or a few sides of a subject that has many sides.