
“Science is what we know, and philosophy is what we don't know.”
1950s, Unpopular Essays (1950)
Source: A New Model of the Universe (1932), p. 33
Context: Philosophy is based on speculation, on logic, on thought, on the synthesis of what we know and on the analysis of what we do not know. Philosophy must include within its confines the whole content of science, religion and art. But where can such a philosophy be found? All that we know in our times by the name of philosophy is not philosophy, but merely "critical literature" or the expression of personal opinions, mainly with the aim of overthrowing and destroying other personal opinions. Or, which is still worse, philosophy is nothing but self-satisfied dialectic surrounding itself with an impenetrable barrier of terminology unintelligible to the uninitiated and solving for itself all the problems of the universe without any possibility of proving these explanations or making them intelligible to ordinary mortals.
“Science is what we know, and philosophy is what we don't know.”
1950s, Unpopular Essays (1950)
“Now the kind of philosophy under which we proceed in the whole and in the part is moral philosophy or ethics; because the whole was undertaken not for speculation but for practice.”
Genus vero philosophie, sub quo hic in toto et parte proceditur, est morale negotium, sive ethica; quia non ad speculandum, sed ad opus inventum est totum et pars.
Letter to Can Grande (Epistle XIII, 40), as translated by Charles Latham in A Translation of Dante's Eleven Letters (1891), Letter XI, §16, p. 199.
Epistolae (Letters)
“Science is spectral analysis. Art is light synthesis.”
Half-Truths and One-And-A-Half Truths (1976)
Source: In Favor of the Sensitive Man and Other Essays
“Philosophy is empty if it isn't based on science. Science discovers, philosophy interprets.”
Source: Attributed in posthumous publications, Einstein and the Poet (1983), p. 98
Otto Neurath (1931) "Physicalism: The Philosophy of the Viennese Circle," in: The Monist, Vol. 41, No. 4 (October, 1931), pp. 618-623; Lead paragraph
1930s
Letter to a Japanese Animal Welfare Society (1961)
Emphasizing his views on philosophy as something abstract and separate from normal life to Isaiah Berlin, in the early 1930s, as quoted in A.J. Ayer: A Life (1999) by Ben Rogers, p. 2.