1.
As long as algebra and geometry have been separated, their progress have been slow and their uses limited; but when these two sciences have been united, they have lent each mutual forces, and have marched together towards perfection.
Joseph-Louis Lagrange
2.
If I had inherited a fortune I should probably not have cast my lot with mathematics.
Joseph-Louis Lagrange
3.
It took the mob only a moment to remove his head; a century will not suffice to reproduce it.
Joseph-Louis Lagrange
4.
I do not know.
[summarising his life's work]
Joseph-Louis Lagrange
5.
The ordinary operations of algebra suffice to resolve problems in the theory of curves.
Joseph-Louis Lagrange
6.
I regarded as quite useless the reading of large treatises of pure analysis: too large a number of methods pass at once before the eyes. It is in the works of application that one must study them; one judges their utility there and appraises the manner of making use of them.
Joseph-Louis Lagrange
7.
The reader will find no figures in this work. The methods which I set forth do not require either constructions or geometrical or mechanical reasonings: but only algebraic operations, subject to a regular and uniform rule of procedure.
Joseph-Louis Lagrange
8.
It has cost them but a moment to cut off that head; but a hundred years will not be sufficient to produce another like it.
Joseph-Louis Lagrange
9.
Newton was the greatest genius that ever existed, and the most fortunate, for we cannot find more than once a system of the world to establish.
Joseph-Louis Lagrange