“They first began teaching their ugly scholastic pseudo-mathematics to their students, then to schoolchildren (forgetting Hardy's warning that ugly mathematics has no permanent place under the Sun).”
"On teaching mathematics", as translated by A. V. Goryunov, in Russian Mathematical Surveys Vol. 53, no. 1 (1998), p. 229–236.
Context: In the middle of the twentieth century it was attempted to divide physics and mathematics. The consequences turned out to be catastrophic. Whole generations of mathematicians grew up without knowing half of their science and, of course, in total ignorance of any other sciences. They first began teaching their ugly scholastic pseudo-mathematics to their students, then to schoolchildren (forgetting Hardy's warning that ugly mathematics has no permanent place under the Sun).
Help us to complete the source, original and additional information
Vladimir I. Arnold 8
Russian mathematician 1937–2010Related quotes

“Unhappiness has nothing to teach, and resignation is ugly.”
Dans un mois, dans un an (1957, Those Without Shadows, translated 1957)

Inaugural lecture for his professorship of mathematical physics at the University of Utrecht (1913), as quoted by Davies, Mansel. Peter Joseph Wilhelm Debye: 1884-1966. Biographical Memoirs of Fellows of The Royal Society, Vol. 16 (1970).

“Ugliness you have to know, beauty you can't teach ~ Disappear”
Lyrics

“Life is an awful, ugly place to not have a best friend.”
Variant: This world is an awful/ugly place not to have a best friend.
Source: Someone Like You (1998)
Methods of Mathematics Applied to Calculus, Probability, and Statistics (1985)

"Sense and Sensibility"
The Common Sense of Science (1951)

“Regardless of whether or not God exists, God has no place in mathematics, at least in my book.”
An Enquiry Concerning Human (and Computer!) [Mathematical] Understanding C.S. Calude, ed., "Randomness & Complexity, from Leibniz to Chaitin", World Scientific, Singapore, (October 2007)
Harald Bohr, [Harald Bohr, Collected Mathematical Works, 1, 1952, Dansk Matematisk Forening, Copenhagen, 3172542, xiii-xxxiv, Looking Backward], p. xxvii
About

“The only two good things in life are doing mathematics and teaching it.”
La vie n'est bonne qu'à deux choses : à faire des mathématiques et à les professer.
quoted by François Arago in Notices biographiques, Volume 2 http://books.google.fr/books?pg=PA662&id=ZzNLAAAAYAAJ#v=onepage&q&f=false, 1854, p. 662.