Immoderate desire is the mark of a child, not a man.

The lie is a condition of life.

You are the bows from which your children as living arrows are sent forth.

Never pick a fight with an ugly person, they've got nothing to lose.

Let him who would move the world first move himself.

I have no desire to make windows into mens souls

Accuracy is the twin brother of honesty; inaccuracy, of dishonesty.

There is nothing more uncommon than common sense.

Where you stand depends on where you sit.

Courage is resistance to fear, mastery of fear - not absence of fear.

Be realistic: Plan for a miracle

A good teacher protects his pupils from his own influence.

Strength does not come from physical capacity. It comes from an indomitable will.

Never put off for tomorrow, what you can do today.

Science may set limits to knowledge, but should not set limits to imagination.

One who gains strength by overcoming obstacles possesses the only strength which can overcome adversity.

The difference between stupidity and genius is that genius has its limits.

Knowing is not enough, we must apply. Willing is not enough, we must do.

One new feature or fresh take can change everything.

An understanding of the natural world is a source of not only great curiosity, but great fulfilment.

Unfortunately, the clock is ticking, the hours are going by. The past increases, the future recedes. Possibilities decreasing, regrets mounting.