There cannot be mental atrophy in any person who continues to observe, to remember what he observes, and to seek answers for his unceasing hows and whys about things.

Ordinary people who know nothing of phonetics or elocution have difficulties in understanding slow speech composed of perfect sounds, while they have no difficulty in comprehending an imperfect gabble if only the accent and rhythm are natural.

Leave the beaten track behind occasionally and dive into the woods. Every time you do you will be certain to find something you have never seen before.

When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us.

Man is an animal which, alone among the animals, refuses to be satisfied by the fulfillment of animal desires.

What this power is I cannot say; all I know is that it exists and it becomes available only when a man is in that state of mind in which he knows exactly what he wants and is fully determined not to quit until he finds it.

Night is a more quiet time to work. It aids thought.