A deed happens in a definite place at a definite time, but if it be sufficiently great and pregnant, its virtue radiates everywhere in time and space. - George Sarton

As I grew older my lectures became simpler; I tried to say fewer things and to say them better, with more humanity. This book continues in a different way the same evolution, but it is not yet as simple as I would have liked to have made it.

Some men are abstract-minded, and they naturally think first of unity and God, of wholeness, of infinity and other such concepts, while the minds of other men are concrete and they cogitate about health and disease, profit and loss. They invent gadgets and remedies; they are less interested in knowing anything than in applying whatever knowledge... to practical problems... The first are called dreamers; the second kind are recognized as practical and useful. History has often proved the shortsightedness of the practical men and vindicated the "lazy" dreamers; it has also proved that the dreamers are often mistaken.

The rationalism of the creative minds was tempered by abundant fantasies, and the supreme beauty of the monuments was probably spoiled by the circumambient vanities and ugliness; in a few cases the Greeks came as close to perfection as it was possible to do, yet they were human and imperfect.