It would be better if you began to teach others only after you yourself have learned something.

Concepts that have proven useful in ordering things easily achieve such authority over us that we forget their earthly origins and accept them as unalterable givens.

Physical concepts are free creations of the human mind, and are not, however it may seem, uniquely determined by the external world.

What I see in Nature is a grand design that we can understand only imperfectly, one with which a responsible person must look at with humility.

It is my conviction that pure mathematical construction enables us to discover the concepts and the laws connecting them, which gives us the key to the understanding of nature ... In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.

Most teachers waste their time by asking question which are intended to discover what a pupil does not know whereas the true art of questioning has for its purpose to discover what pupils knows or is capable of knowing.

One picture is worth a thousand words