It behooves those who devote themselves to observation to be impressed by this truth (i.e., that many "facts" grow old) and to realize that the best work is only good in relation to its time and that it awaits another, more exact and more complete.

Recherches Anatomiques, Pathologiques et Therapeutiques sur la Maladie Connue Sous les Noms de Gastro-Enterite (p. vii),