“The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are”
Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, Vol. 123, No. 792 http://doi.org/10.1098/rspa.1929.0094 (6 April 1929)
Context: The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known, and the difficulty is only that the exact application of these laws leads to equations much too complicated to be soluble. It therefore becomes desirable that approximate practical methods of applying quantum mechanics should be developed, which can lead to an explanation of the main features of complex atomic systems without too much computation.
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Paul Dirac 23
theoretical physicist 1902–1984Related quotes

TED talk on beauty and truth in physics —video timecode 14m28s (March 2007) http://ted.com/index.php/talks/murray_gell_mann_on_beauty_and_truth_in_physics.html.
"The Magic of Science" in Imperial Oil Review (Spring, 1994) http://sites.utoronto.ca/jpolanyi/public_affairs/public_affairs4f.html.
Context: It is not the laws of physics that make science possible but the unprovable proposition that there exists a grand design underlying the physical world. And not just any old "grand design" but one that is accessible to the limited senses and modest reasoning powers of the species to which we belong. Scientists subscribe with such conviction to this article of faith that they are willing to commit a lifetime to the pursuit of scientific discovery. It is hardly surprising that an activity so magical is also undefinable. Science is what scientists do. And what they do is look around themselves for messages written in the sky, the earth, the oceans and all living things – messages that tell of the unity of creation. These messages have been there – unseen, though at times written in letters miles high – since the dawn of history. But we have just passed through an epoch in which, quite suddenly, scientists seem to have learnt speed reading. Discoveries have been coming at an unprecedented pace. In the wake of such a period it is common to consider that we may be approaching the point where all that is readable in nature will have been read. We should be skeptical of such claims. Success in reading some messages brings with it a temporary blindness to others. We forget that between the words written in black in nature's book there are likely to be messages of equal importance written in white. It is a truism that success in science comes to the individuals who ask the right questions.

The Evolution of the Physicist's Picture of Nature (1963)
Context: It seems to be one of the fundamental features of nature that fundamental physical laws are described in terms of a mathematical theory of great beauty and power, needing quite a high standard of mathematics for one to understand it. You may wonder: Why is nature constructed along these lines? One can only answer that our present knowledge seems to show that nature is so constructed. We simply have to accept it. One could perhaps describe the situation by saying that God is a mathematician of a very high order, and He used very advanced mathematics in constructing the universe. Our feeble attempts at mathematics enable us to understand a bit of the universe, and as we proceed to develop higher and higher mathematics we can hope to understand the universe better.

[Jon Fripp, Michael Fripp, Deborah Fripp, Speaking of Science: Notable Quotes on Science, Engineering, and the Environment, https://books.google.com/books?id=44ihCUS1XQMC&pg=PA45, 2000, Newnes, 978-1-878707-51-2, 45]

Part 2; Cited in: Evgenii Rudnyi (2013).
Thermodynamics of Evolution (1972)

As quoted in American Journal of Physics, Vol. 14 | (1946), p. 248