(source) 
Hermann Weyl
(9 Nov 1885  8 Dec 1955)

Science Quotes by Hermann Weyl (14 quotes)
A modern mathematical proof is not very different from a modern machine, or a modern test setup: the simple fundamental principles are hidden and almost invisible under a mass of technical details.
— Hermann Weyl
Before you generalize, formalize, and axiomatize there must be mathematical substance.
— Hermann Weyl
In geometric and physical applications, it always turns out that a quantity is characterized not only by its tensor order, but also by symmetry.
— Hermann Weyl
Logic is the hygiene the mathematician practices to keep his ideas healthy and strong.
— Hermann Weyl
My work always tried to unite the true with the beautiful, but when I had to choose one or the other, I usually chose the beautiful.
— Hermann Weyl
My work has always tried to unite the true with the beautiful and when I had to choose one or the other, I usually chose the beautiful.
— Hermann Weyl
Numbers have neither substance, nor meaning, nor qualities. They are nothing but marks, and all that is in them we have put into them by the simple rule of straight succession.
— Hermann Weyl
Our federal income tax law defines the tax y to be paid in terms of the income x; it does so in a clumsy enough way by pasting several linear functions together, each valid in another interval or bracket of income. An archaeologist who, five thousand years from now, shall unearth some of our income tax returns together with relics of engineering works and mathematical books, will probably date them a couple of centuries earlier, certainly before Galileo and Vieta.
— Hermann Weyl
Symmetry, as wide or as narrow as you may define its meaning, is one idea by which man through the ages has tried to comprehend and create order, beauty and perfection.
— Hermann Weyl
The constructions of the mathematical mind are at the same time free and necessary. The individual mathematician feels free to define his notions and set up his axioms as he pleases. But the question is will he get his fellowmathematician interested in the constructs of his imagination. We cannot help the feeling that certain mathematical structures which have evolved through the combined efforts of the mathematical community bear the stamp of a necessity not affected by the accidents of their historical birth. Everybody who looks at the spectacle of modern algebra will be struck by this complementarity of freedom and necessity.
— Hermann Weyl
The Greeks made Space the subjectmatter of a science of supreme simplicity and certainty. Out of it grew, in the mind of classical antiquity, the idea of pure science. Geometry became one of the most powerful expressions of that sovereignty of the intellect that inspired the thought of those times. At a later epoch, when the intellectual despotism of the Church, which had been maintained through the Middle Ages, had crumbled, and a wave of scepticism threatened to sweep away all that had seemed most fixed, those who believed in Truth clung to Geometry as to a rock, and it was the highest ideal of every scientist to carry on his science “more geometrico.”
— Hermann Weyl
We are not very pleased when we are forced to accept a mathematical truth by virtue of a complicated chain of formal conclusions and computations, which we traverse blindly, link by link, feeling our way by touch. We want first an overview of the aim and of the road; we want to understand the idea of the proof, the deeper context.
— Hermann Weyl
Without the concepts, methods and results found and developed by previous generations right down to Greek antiquity one cannot understand either the aims or achievements of mathematics in the last fifty years.
— Hermann Weyl
~~[Misattributed]~~ It was Galileo who said, “Measure what is measurable, and make measurable what is not so.”
— Hermann Weyl
See also:
 9 Nov  short biography, births, deaths and events on date of Weyl's birth.