Schopenhauer, Die Welt als Wille und Vorstellung, vol. ii, pp. 608 et seq.
"Perhaps there is scarcely a man," wrote Malthus, a clergyman as well as one of the profoundest thinkers of his day (Essay on the Principle of Population, 1798, Ch. XI), "who has once experienced the genuine delight of virtuous love, however great his intellectual pleasures may have been, that does not look back to the period as the sunny spot in his whole life, where his imagination loves to bask, which he recollects and contemplates with the fondest regrets, and which he would most wish to live over again. The superiority of intellectual to sexual pleasures consists rather in their filling up more time, in their having a larger range, and in their being less liable to satiate, than in their being more real and essential."
The whole argument of the fourth volume of these Studies, on "Sexual Selection in Man," points in this direction.