Henri Poincaré

In the presence of phenomena which are beyond our comprehension, we must not seek to invent explanations.

The art of reasoning consists in seeing the logical connections between facts so completely that the mind never loses sight of them.

Happiness is the only sanction of life; where happiness fails, life fails.

The principles of logic are the principles of truth.

Every definition implies an axiom.

The future of mathematics lies in its applications to physics.

To teach is to learn twice.

The beauty of mathematics only shows itself to the patient seeker.

We cannot know the whole truth, but we can approach it.

Imagination is more important than knowledge.

The joy of discovery is the greatest reward of the scientist.

Mathematics is the poetry of logical ideas.

In science, as in love, one must first choose the object of study.

The universe is not only stranger than we imagine, it is stranger than we can imagine.

Persistence in error is the road to madness.

The true logic of science is the logic of discovery.

Life without love is like a tree without blossoms or fruit.

Geometry drew me; I loved to draw its figures.

The differential equation is the most powerful tool in the hands of the mathematician.

To doubt is difficult; to affirm, easy.