“Formulae are the anaesthetics of thought, not its stimulants”

Entry (1950)
Eric Hoffer and the Art of the Notebook (2005)

Hayek's Journey: The Mind of Friedrich Hayek (2003)

Part 1, Chapter 9 (page 31)
Notes from Underground (1864)

The scientific work of Georges Lemaître (1968), P.A.M. Dirac, Commentarii (Pontifical Academy of Sciences), vol 2, 11, pp. 1–18.

On the Uses and Transformations of Linear Algebra (1875)
Context: The familiar proposition that all A is B, and all B is C, and therefore all A is C, is contracted in its domain by the substitution of significant words for the symbolic letters. The A, B, and C, are subject to no limitation for the purposes and validity of the proposition; they may represent not merely the actual, but also the ideal, the impossible as well as the possible. In Algebra, likewise, the letters are symbols which, passed through a machinery of argument in accord ance with given laws, are developed into symbolic results under the name of formulas. When the formulas admit of intelligible interpretation, they are accessions to knowledge; but independently of their interpretation they are invaluable as symbolical expressions of thought. But the most noted instance is the symbol called the impossible or imaginary, known also as the square root of minus one, and which, from a shadow of meaning attached to it, may be more definitely distinguished as the symbol of semi-inversion. This symbol is restricted to a precise signification as the representative of perpendicularity in quaternions, and this wonderful algebra of space is intimately dependent upon the special use of the symbol for its symmetry, elegance, and power.

Source: The Limits of Evolution, and Other Essays, Illustrating the Metaphysical Theory of Personal Ideaalism (1905), Modern Science and Pantheism, p.60-1

Undated mauscript c 1941.Kettle's Yard archive,Cambridge.

The Evolution of Physics (1938) (co-written with Leopold Infeld)
1930s

Contributions of Jane Wagner