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

- Leonhard Euler

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 priv…

- Leonhard Euler

To those who ask what the infinitely small quantity in mathematics is, we answer that it is actually zero. Hence there are not so many mysteries hidd…

- Leonhard Euler

A function of a variable quantity is an analytic expression composed in any way whatsoever of the variable quantity and numbers or constant quantitie…

- Leonhard Euler

The kind of knowledge which is supported only by observations and is not yet proved must be carefully distinguished from the truth; it is gained by i…

- Leonhard Euler

Now I will have less distraction.

- Leonhard Euler

For since the fabric of the universe is most perfect and the work of a most wise Creator, nothing at all takes place in the universe in which some ru…

- Leonhard Euler

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

- Leonhard Euler

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

- Leonhard Euler