And as for a life deliberately devoted to pleasure as an end — why, the greatest happiness is the happiness that comes as a by-product of striving to do what must be done, even though sorrow is met in the doing.

Theodore Roosevelt (1858–1919) American politician, statesman, conservationist, writer; US President (1901–09)

Autobiography, ch. 9 “Outdoors and Indoors” (1913)
    (Source)

See Johnson (1753).