You bring me the deepest joy that can be felt by a man whose invincible belief is that Science and Peace will triumph over Ignorance and War, that nations will unite, not to destroy, but to build, and that the future will belong to those who will have done most for suffering humanity.

Without theory, practice is but routine born of habit. Theory alone can bring forth and develop the spirit of inventions.

Every chemical substance, whether natural or artificial, falls into one of two major categories, according to the spatial characteristic of its form. The distinction is between those substances that have a plane of symmetry and those that do not. The former belong to the mineral, the latter to the living world.

When you believe you have found an important scientific fact, and are feverishly curious to publish it, constrain yourself for days, weeks, years sometimes, fight yourself, try and ruin your own experiments, and only proclaim your discovery after having exhausted all contrary hypotheses. But when, after so many efforts you have at last arrived at a certainty, your joy is one of the greatest which can be felt by a human soul.

... by chance you will say, but chance only favors the mind which is prepared.

Let me tell you the secret that has led me to my goal. My strength lies solely in my tenacity.

When one works and imagines and dreams of nothing else than the search for answers that God has posed, it is difficult to be so still.