Depth and strength of a human character are defined by its moral reserves.

My body is not a tomb for animals.

But to me all sciences seem vain and full of error that are not born of experience, mother of all certainty, and do not terminate in an actual experience.

I have discovered that a screw-shaped device such as this, if it is well made from starched linen, will rise in the air if turned quickly.

It is useful to constantly observe, note, and consider.

Even the richest soil, if left uncultivated will produce the rankest weeds.

Nature never breaks her own laws.