As for everything else, so for a mathematical theory: beauty can be perceived but not explained.

degree and win a Fellowship by competitive examination. Formerly when mathematicians spoke of "groups" they had meant permutation groups. While editing these volumes he was suffering from a painful internal malady to which he succumbed on 26 January 1895 in the 74th year of his age.

He postulated the Cayley–Hamilton theorem—that every square matrix is a root of its own characteristic polynomial and verified it for matrices of order 2 and 3. He was the first to define the concept of a group in the modern way—as a set with a binary operation satisfying certain laws.