Evolution pays and that is why there is evolution

A man's own addition to what he learns is cement to bind an otherwise loose heap of stones into a structure of unity, strength, and use.

Error held as truth has much the effect of truth. In politics and religion this fact upsets many confident predictions.

Ignorance may find a truth on its doorstep that erudition vainly seeks in the stars.

We despair of changing the habits of men, still we would alter institutions, the habits of millions of men.

Ten builders rear an arch, each in turn lifting it higher; but it is the tenth man, who drops in the keystone, who hears our huzzas.

Nature is full of by-ends. A moth feeds on a petal, in a moment the pollen caught on its breast will be wedding this blossom to another in the next county.