Something towards this end is being accomplished by the introduction of experimental research and scientific study in general in our schools and colleges. It is hoped that something towards the same end may be accomplished through study of the history of the development of science. Scarcely anything is more illuminative than to observe critically the mistakes of our predecessors, noting how natural the mistakes were and how tenaciously they were held to, how strenuously defended. Most of all it would be of value to note that the false inductions which have everywhere hampered the progress of science have been, from the stand-point of the generation in which they originated, for the most part logical inductions. We have seen that the Ptolemaic scheme of the universe, false though it was in its very essentials, yet explained in what may be termed a thoroughly scientific fashion the observed phenomena. It is one way of expressing a fact to say that the sun moves across the heavens from the eastern to the western horizon; and for most practical purposes this assumption answers perfectly. It is only when we endeavor to extend the range of theoretical astronomy, and to gain a correct conception of the mechanism of the universe as a whole, that the essentially faulty character of the geocentric conception becomes apparent.
And so it is in many another field; the false generalizations and hasty inductions serve a temporary purpose. Our only quarrel with them is that they tend through a sort of inertia to go forever unchanged. It requires a powerful thrust to divert the aggregate mind of our race from a given course, nor is the effect of a new impulse immediately appreciable; that is why the masses of the people always lag a generation or two behind the advanced thinkers. A few receptive minds, cognizant of new observations that refute an old generalization, accept new laws, and, from the vantage-ground thus gained, reach out after yet other truths. But, for the most part, the new laws thus accepted by the leaders remain unknown to the people at large for at least one or two generations. It required about a century for the heliocentric doctrine of Copernicus to begin to make its way.
In this age of steam and electricity, progress is more rapid, and the greatest scientific conception of the nineteenth century, the Darwinian theory, may be said to have made something that approaches an absolute conquest within less than half a century. This seems a marvellously sudden conquest, but it must be understood that it is only the crude and more tangible bearings of the theory that have thus made their way. The remoter consequences of the theory are not even suspected by the great majority of those who call themselves Darwinians to-day. It will require at least another century for these ideas to produce their full effect. Then, in all probability, it will appear that the nineteenth century was the most revolutionary epoch by far that the history of thought has known. And it owes this proud position to the fact that it was the epoch in all history most fully subject to the dominant influence of inductive science. Thanks to this influence, we of the new generation are able to start out on a course widely divergent from the path of our ancestors. Our leaders of thought have struggled free from the bogs of superstition, and are pressing forward calmly yet with exultation towards the heights.
APPENDIX
(p. 95). J. J. Thompson, D.Sc., LL.D., Ph.D., F.R.S.,etc., Electricity
and Matter, p. 75 ff., New York, 1904. The Silli-man Lectures, delivered
at Yale University, May, 1903.
(p. 96). Ibid., pp. 88, 89. 3 (p- 97)- Ibid., p. 89.
(p. 97). Ibid., p. 87.
(p. 102). George F. Kunz, "Radium and its Wonders," in the Review of
Reviews for November, 1903, p. 589.
(p. 105). E. Rutherford, Radio-Activity, p. 330, Cambridge, 1904.
(p. 106). Ibid., p. 330.
(p. 106). Compte Rendu, pp. 136, 673, Paris, 1903.
(p. 106). Revue Scientifique, April 13, 1901. 10 (p. 106). Compte Rendu,
p. 136, Paris, 1903.
(p. 108). J. J. Thompson, Electricity and Matter, p. 162, New York,
1904.
(p. —). E. Rutherford, Radio-Activity, p. 340, Cambridge, 1904.
(p. 185). Dr. Duclaux, who was one of Pasteur's chief assistants, and
who succeeded him in the directorship of the Institute, died in 1903. He
held a professorship in the University of Paris during the later years
of his life, and his special studies had to do largely with the chemical
side of bacteriology.
(p. 217). Lord Kelvin's estimate as quoted was expressed to the writer
verbally. I do not know whether he has anywhere given a similar written
verdict.
A LIST OF SOURCES I.—PERIOD COVERED BY VOLUME I.
An ax agoras. See vol. i., p. 240.
Archimedes. See vol. i., p. 196.