Although to penetrate into the intimate mysteries of nature and thence to learn the true causes of phenomena is not allowed to us, nevertheless it can happen that a certain fictive hypothesis may suffice for explaining many phenomena.

Transcendental [numbers], They transcend the power of algebraic methods.

I soon found an opportunity to be introduced to a famous professor Johann Bernoulli. ... True, he was very busy and so refused flatly to give me private lessons; but he gave me much more valuable advice to start reading more difficult mathematical books on my own and to study them as diligently as I could; if I came across some obstacle or difficulty, I was given permission to visit him freely every Sunday afternoon and he kindly explained to me everything I could not understand.

Madam, I have come from a country where people are hanged if they talk.

Now I will have less distraction.

For the sake of brevity, we will always represent this number 2.718281828459... by the letter e.

Logic is the foundation of the certainty of all the knowledge we acquire.