Volumes might be written upon the impiety of the pious

Man needed one moral constitution to fit him for his original state; he needs another to fit him for his present state; and he has been, is, and will long continue to be, in process of adaptation.

Evil perpetually tends to disappear.

The truth is, that those who have never entered upon scientific pursuits know not a tithe of the poetry by which they are surrounded.

The current opinion that science and poetry are opposed is a delusion.

All evil results from the non-adaptation of constitution to conditions. This is true of everything that lives. Does a shrub dwindle in poor soil, or become sickly when deprived of light, or die outright if removed to a cold climate? it is …

Progress, therefore, is not an accident, but a necessity.