Max Planck

The application of Boltzmann's procedure to could only succeed if one considered radiation as atomistic.., as a combination of... quanta... of a specific size.., known... by the previous measurements.

1942

In the limiting case, [entropy] stays the same. If it increases.., the process is irreversible. If it remains the same.., the process is reversible... [i.e.,] you can let it run backwards.

1942

In physical-chemical equilibria, an American was faster... John Willard Gibbs... Regarding radiation equilibrium... I... built the foundations.

1942

Energy remains constant and entropy always grows and can never be reduced... [T]his is the essence of the second law of thermodynamics...the entropy of a system of bodies can... only increase.

1942

Both religion and science require a belief in God. For believers, God is in the beginning, and for physicists He is at the end of all considerations… To the former He is the foundation, to the latter, the crown of the edifice of every generalized world view.

Scientific Autobiography and Other Papers as translated by F. Gaynor (1949), p. 184, 1937

Natural science wants man to learn, religion wants him to act.

1937

Religion and natural science are fighting a joint battle in an incessant, never relaxing crusade against scepticism and against dogmatism, against disbelief and against superstition, and the rallying cry in this crusade has always been, and always will be: "On to God!"

1937

Anybody who has been seriously engaged in scientific work of any kind realizes that over the entrance to the gates of the temple of science are written the words: Ye must have faith. It is a quality which the scientist cannot dispense with.

Epilogue, p. 214, 1932

But science sets out confidently on the endeavor finally to know the thing in itself, and even though we realize that this ideal goal can never be completely reached, still we struggle on towards it untiringly. And we know that at every step of the way each effort will be richly rewarded.

Causation and free will: the problem stated, p. 139f., 1932

The first and most important quality of all scientific ways of thinking must be the clear distinction between the outer object of observation and the subjective nature of the observer.

Causation and free will: the problem stated, p. 139, 1932

Again and again the imaginary plan on which one attempts to build up that order breaks down and then we must try another. This imaginative vision and faith in the ultimate success are indispensable. The pure rationalist has no place here.

Epilogue, p. 215, 1932

It is not the possession of truth, but the success which attends the seeking after it, that enriches the seeker and brings happiness to him.

Is the external world real?, p. 83, 1932

We have no right to assume that any physical laws exist, or if they have existed up to now, that they will continue to exist in a similar manner in the future.

The Universe in the Light of Modern Physics (1931), 1931

I regard consciousness as fundamental. I regard matter as derivative from consciousness. We cannot get behind consciousness. Everything that we talk about, everything that we regard as existing, postulates consciousness.

The Observer (London, England) (25 January 1931), p. 17, 1931

The energy and entropy of the world have no meaning, because such quantities admit of no accurate definition.

Treatise on Thermodynamics, 1903, Translated by Alexander Ogg, 1903