Quotes from book
The Analytical Theory of Heat

Name: The Analytical Theory of Heat
Author: Joseph Fourier

Joseph Fourier Original title Théorie analytique de la chaleur (French, 1822)

In this pioneering work of mathematics, Joseph Fourier shows how the conduction of heat in solid bodies can be analyzed in terms of an infinite mathematical series. Known as the Fourier Series, this was the first correct theory on heat diffusion and continues to be used in present-day analysis. For anyone interested in the theory of heat or in the mathematical tools developed by Fourier, this classic work remains indispensable. Born the son of a French tailor, JOSEPH FOURIER (1768-1830) was a mathematician, Egyptologist, and politician whose strong influence on mathematical physics continues to this day. His other works include Description of Egypt and Analysis of Determinate Equations.

“Profound study of nature is the most fertile source of mathematical discoveries.”

Joseph Fourier book The Analytical Theory of Heat

Source: The Analytical Theory of Heat (1878), Ch. 1, p. 7

“The analytical equations, unknown to the ancient geometers, which Descartes was the first to introduce into the study of curves and surfaces, are not restricted to the properties of figures, and to those properties which are the object of rational mechanics; they extend to all general phenomena. There cannot be a language more universal and more simple, more free from errors and from obscurities, that is to say more worthy to express the invariable relations of natural things.
Considered from this point of view, mathematical analysis is as extensive as nature itself; it defines all perceptible relations, measures times, spaces, forces, temperatures; this difficult science is formed slowly, but it preserves every principle which it has once acquired; it grows and strengthens itself incessantly in the midst of the many variations and errors of the human mind.
Its chief attribute is clearness; it has no marks to express confused notions. It brings together phenomena the most diverse, and discovers the hidden analogies which unite them.”

Joseph Fourier book The Analytical Theory of Heat

Preliminary Discourse, p.7 Note: often quoted as Mathematics [or mathematical analysis] compares the most diverse phenomena and discovers the secret analogies that unite them.
The Analytical Theory of Heat (1878)

“Primary causes are unknown to us; but are subject to simple and constant laws, which may be discovered by observation, the study of them being the object of natural philosophy.
Heat, like gravity, penetrates every substance of the universe, its rays occupy all parts of space. The object of our work is to set forth the mathematical laws which this element obeys. The theory of heat will hereafter form one of the most important branches of general physics.”

Joseph Fourier book The Analytical Theory of Heat

Source: The Analytical Theory of Heat (1878), Ch. 1, p. 1

“The principles of the theory are derived, as are those of rational mechanics, from a very small number of primary facts”

Joseph Fourier book The Analytical Theory of Heat

Source: The Analytical Theory of Heat (1878), Ch. 1, p. 6
Context: If we consider further the manifold relations of this mathematical theory to civil uses and the technical arts, we shall recognize completely the extent of its applications. It is evident that it includes an entire series of distinct phenomena, and that the study of it cannot be omitted without losing a notable part of the science of nature.
The principles of the theory are derived, as are those of rational mechanics, from a very small number of primary facts, the causes of which are not considered by geometers, but which they admit as the results of common observations confirmed by all experiment.