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.

Preface - A History of Science Vol.1 Ancient Science Through the Golden Age of Greece (1952)