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

Doubt is the beginning, not the end, of wisdom.

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.

Some young folks have wind-fall minds, prematurely detached from the tree of knowledge for a life-long sourness and pettiness.

When we try to imagine a chaos we fail. ... In its very fiber the mind is an order and refuses to build a chaos.

Is any knowledge worthless? Try to think of an example.

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