Nature does nothing in vain.

The search for truth is in one way hard and in another way easy, for it is evident that no one can master it fully or miss it wholly. But each adds a little to our knowledge of nature, and from all the facts assembled there arises a certain grandeur.

No one finds fault with defects which are the result of nature.

I say that habit's but a long practice, friend, And this becomes men's nature in the end

The one who woke up thinking he lives for nothing, has lost a night in vain.

Nothing is made in vain, but the fly came near it