There exists a passion for comprehension, just as there exists a passion for music. That passion is rather common in children, but gets lost in most people later on. Without this passion there would be neither mathematics nor natural science.

Nothing great in the world was ever accomplished without passion.

Passion goes, Boredom remains.

The ruling passion, be it what it will, The ruling passion conquers reason still.

The passions are the winds which fill the sails of the vessel; they sink it at times, but without them it would be impossible to make way.

Passion is like genius: a miracle.

The mind is the soul's eye, not its source of power. That lies in the heart, in other words, in the passions.

Nobody notices postmen, yet they have passions like other men.

Nothing great in the world has been accomplished without passion.

Three passions, simple but overwhelmingly strong, have governed my life: the longing for love, the search for knowledge, and the unbearable pity for the suffering of mankind.