"1. The Primary, or Paleozoic age, comprising the lower Silurian, the upper Silurian, and the Devonian. During this age there were no air-breathing animals. The fishes were masters of creation. We may therefore call it the Reign of Fishes.
"2. The Secondary age, comprising the Carboniferous, the Trias, the Oölite, and the Cretaceous formations. This is the epoch in which air-breathing animals first appear. The Reptiles predominated over the other classes, and we may therefore call it the 'Reign of Reptiles.'
"3. The Tertiary age, comprising the Tertiary formation. During this age terrestrial mammals of great size abound. This is the Reign of Mammals.
"4. The Modern age, characterized by the appearance of the most perfect of created beings."
The majority of mankind trouble themselves but little whether progress is made in any one of the branches of science or not. Man has no time to think seriously of anything except to provide food for his family. The priest does his thinking, and he is made to contribute part of his labor to support the holy man who does the thinking for him. All he knows is that his soul or his spirit, his hereafter, and his God are well cared for, and he pays for it. Yet every man ought to understand that all his rights, civil and political--all the freedom he enjoys--he has to thank science for procuring and securing.
"Shall it be seriously objected to the application of the sciences to philosophical problems that its results are not agreeable? That the truth is not always agreeable, nor always consolatory, nor always religious, nor always acceptable, is as well known as the old experience of the almost total absence of reward, either external or internal, provided for its exemplars. What this or that man may understand by a governing reason, an absolute power, a universal soul, a personal God ... is his own affair. The theologians, with their articles of faith, must be left to themselves; so of the naturalists with their science; they both proceed by different routes.... The same bloody hatred with which science was once persecuted by religious fanaticism would revive now, and with it the Inquisition and Auto-da-fé, and all the horrors with which a refined zealotism has tortured humanity would be resorted to, to satisfy the wishes of the theological cutthroats. A man in advance of his age beholds the struggle of the contending parties from a high point of view, and sees in the eccentricities of this contest merely the natural and necessary expression of the opposing elements which agitate our time. No one can doubt that truth will finally emerge the victor. It certainly will not be long before the battle becomes general. Is the victory doubtful? The struggle is unequal; the opponents cannot stand against the trenchant arm of physical and physiological Materialism, which fights with facts, that everyone can comprehend, while the opponents fight with suppositions and presumptions" (Büchner).