Knowledge, reason, self-consciousness, will, are the attributes of Man."(1) It has been a slow and gradual growth, and not until within the past century has science organized knowledge--so searched out the secrets of Nature, as to control her powers, limit her scope and transform her energies.

The victory is so recent that the mental attitude of the race is not yet adapted to the change.

A large proportion of our fellow creatures still regard nature as a playground for demons and spirits to be exorcised or invoked.
(1) Sir E.Ray Lankester: Romanes Lecture, "Nature and Man," Oxford Univ.

Press, 1905, p.

21.
Side by side, as substance and shadow--"in the dark backward and abysm of time," in the dawn of the great civilizations of Egypt and Babylon, in the bright morning of Greece, and in the full noontide of modern life, together have grown up these two diametrically opposite views of man's relation to nature, and more particularly of his personal relation to the agencies of disease.
The purpose of this course of lectures is to sketch the main features of the growth of these two dominant ideas, to show how they have influenced man at the different periods of his evolution, how the lamp of reason, so early lighted in his soul, burning now bright, now dim, has never, even in his darkest period, been wholly extinguished, but retrimmed and refurnished by his indomitable energies, now shines more and more towards the perfect day.