It is good even to be a fisherman in summer and in winter.
(Henry David Thoreau (1817-1862), U.S. philosopher, author, naturalist. A Week on the Concord and Merrimack Rivers (1849), in The Writings of Henry David Thoreau, vol. 1, p. 21, Houghton Mifflin (1906).)
For one swallow does not make a summer, nor does one day; and so too one day, or a short time, does not make a man blessed and happy.
(Aristotle (384-322 B.C.), Greek philosopher. Nichomachean Ethics I.7: 1098a18-19, Complete Works of Aristotle, trans. by W.D. Ross, ed. Jonathan Barnes, Princeton University Press (1984).
An important qualification of Aristotle's definition of happiness.)