THE UNITY OF PHYSICAL SCIENCE 13 



among those who knew it, few cared to know anything about the 

 subject." That the attitude of the educated public towards biolog- 

 ical science could have been thus indifferent, if not inimical, forty 

 years ago, seems strange enough now even to those of us who have 

 witnessed in part the scientific progress subsequent to that epoch. 

 But this was a memorable epoch, marked by the advent of the great 

 intellectual awakening ushered in by the generalizations of Darwin, 

 Wallace, Spencer, and their coadjutors. And the quarter of a cen- 

 tury which immediately followed this epoch appears, as we look back 

 upon it, like an heroic age of scientific achievement. It was an age 

 during which some men of science, and more men not of science, 

 lost their heads temporarily, if not permanently; but it was also an 

 age during which most men of science, and thinking people in gen- 

 eral, moved forward at a rate quite without precedent in the history 

 of human advancement. A new, and a greatly enlarged, view of the 

 universe was introduced in the doctrine of evolution, advanced and 

 opposed, alike vigorously, chiefly by reason of its biological appli- 

 cations and implications. Galileo, Newton, and Laplace had given 

 us a system of the inorganic world; Darwin, Spencer, and their 

 followers have foreshadowed a system which includes the organic 

 world as well. 



The astonishing progress of biology in recent times furnishes the 

 most convincing evidence of the unity and the efficiency of the 

 methods of physical science in the interpretation of natural phe- 

 nomena. For the biologist has followed the same methods, with 

 changes appropriate to his subject-matter only, as those found 

 fruitful in astronomy, chemistry, and all the rest. And whatever 

 may be the increased complexity of the organic over the inorganic 

 world, or however high the factor of life may seem to raise the pro- 

 blems of biology above the plane of the other physical sciences, 

 there has appeared no sufficient reason, as yet, to doubt either the 

 validity or the adequacy of those methods. 



Moreover, the interrelations of biology with chemistry and phys- 

 ics especially are yearly growing more and more extended and in- 

 timate through the rapidly expanding researches of bacteriology, 

 physiology, and physiological chemistry, plant and animal patho- 

 logy, and so on, up through cytology to the embryology of the higher 

 forms of life. Through the problems of these researches also we 

 are again brought face to face, sooner or later, with the problems of 

 molecular science. 



And finally, what may be said of anthropology, which is at once 

 the most interesting and the most novel of the physical sciences, 

 interesting by reason of its subject-matter, novel by reason of its 

 applications? Some of us, perhaps, might be inclined to demur from 

 a classification which makes man, along with matter, a fit object 



