Thought is only a flash between two long nights, but this flash is everything.

- Henri Poincare

Science is facts.

- Henri Poincare

Point set topology is a disease from which the human race will soon recover.

- Henri Poincare

Science is built up of facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house.

- Henri Poincare

Ideas rose in clouds; I felt them collide until pairs interlocked, so to speak, making a stable combination.

- Henri Poincare

Mathematicians do not study objects, but relations between objects.

- Henri Poincare

It is through science that we prove, but through intuition that we discover.

- Henri Poincare

To doubt everything, or, to believe everything, are two equally convenient solutions; both dispense with the necessity of reflection.

- Henri Poincare

If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living.

- Henri Poincare

A small error in the former will produce an enormous error in the latter.

- Henri Poincare

It is far better to foresee even without certainty than not to foresee at all.

- Henri Poincare

Mathematics is the art of giving the same name to different things.

- Henri Poincare

It has adopted the geometry most advantageous to the species or, in other words, the most convenient.

- Henri Poincare

In the old days when people invented a new function they had something useful in mind.

- Henri Poincare

How is an error possible in mathematics?

- Henri Poincare

Mathematicians are born, not made.

- Henri Poincare

It is the harmony of the diverse parts, their symmetry, their happy balance; in a word it is all that introduces order, all that gives unity, that permits us to see clearly and to comprehend at once both the ensemble and the details.

- Henri Poincare

Geometry is not true, it is advantageous.

- Henri Poincare

If we knew exactly the laws of nature and the situation of the universe at the initial moment, we could predict exactly the situation of the same universe at a succeeding moment.

- Henri Poincare

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.

- Henri Poincare