Do not fear to be eccentric in opinion, for every opinion now accepted was once eccentric.
It's easy to fall in love. The hard part is finding someone to catch you.
Most people would rather die than think; in fact, they do so.
The world is full of magical things patiently waiting for our wits to get sharper.
There is no reason to suppose that the world had a beginning at all. The idea that things must have a beginning is really due to the poverty of our thoughts.
Fear is the main source of superstition, and one of the main sources of cruelty. To conquer fear is the beginning of wisdom, in the pursuit of truth as in the endeavour after a worthy manner of life.
I would never die for my beliefs, cause I might be wrong.
Is there any knowledge in the world which is so certain that no reasonable man could doubt it?
Man needs, for his happiness, not only the enjoyment of this or that, but hope and enterprise and change.
Clarity, above all, has been my aim.
The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
The universe may have a purpose, but nothing we know suggests that, if so, this purpose has any similarity to ours.
What men really want is not knowledge but certainty.
To be without some of the things you want is an indispensable part of happiness.
All serious innovation is only rendered possible by some accident enabling unpopular persons to survive.
The good life is inspired by love and guided by knowledge.
Anything you're good at contributes to happiness.
No one ever gossips about the virtues of others.
It is a waste of energy to be angry with a man who behaves badly, just as it is to be angry with a car that won't go.
What is wanted is not the will to believe, but the will to find out, which is the exact opposite.
Science is what you know, philosophy is what you don't know.
Beware the man of a single book.
Of all forms of caution, caution in love is perhaps the most fatal to true happiness.
A life without adventure is likely to be unsatisfying, but a life in which adventure is allowed to take whatever form it will is sure to be short.
The morality of work is the morality of slaves, and the modern world has no need of slavery.