The worst part is not in making a mistake but in trying to justify it, instead of using it as a heaven-sent warning of our mindlessness or our ignorance.

The brain is a world consisting of a number of unexplored continents and great stretches of unknown territory.

Every man if he so desires becomes sculptor of his own brain.

In summary, all great work is the fruit of patience and perseverance, combined with tenacious concentration on a subject over a period of months or years.

Unfortunately, nature seems unaware of our intellectual need for convenience and unity, and very often takes delight in complication and diversity.

There are no small problems. Problems that appear small are large problems that are not understood

It is idle to dispute with old men. Their opinions, like their cranial sutures, are ossified.

In adult centers the nerve paths are something fixed, ended, immutable. Everything may die, nothing may be regenerated.

That which enters the mind through reason can be corrected. That which is admitted through faith, hardly ever.

To know the brain...is equivalent to ascertaining the material course of thought and will, to discovering the intimate history of life in its perpetual duel with external forces.

Nothing inspires more reverence and awe in me than an old man who knows how to change his mind.

Call no man happy, said Shadow, until he is dead

New friends can often have a better time together than old friends.

Whatever may happen, it must be of new hope or of new courage to me!

There is a point at which everything becomes simple and there is no longer any question of choice because all you have staked will be lost if you look back. Life's point of no return.

My child was one of Nature's Tories pitted against a mother who was one of nurture's Lefties: it was no contest.

Everyone doubts themselves. It's just a matter of admitting it or not.

As some species die out, forms better adapted to utilize the obstacles against which they struggled in vain come into being.

When you find your voice, your life takes on grace.

You'd think I was shoving bamboo splinters under your nails. (Alice from Twilight)

Nobody who has not been up in the sky on a glorious morning can possibly imagine the way a pilot feels in free heaven.