Charles Bonnet, the Swiss naturalist, "religious cosmologist," and philosopher, was born and died in Geneva. An original if eccentric thinker, Bonnet was widely read and influential. He was early attracted to natural history, and especially to entomology, by René Réaumur's work and by the Abbé Pluche's apologetic, Spectacle de la nature (1732). At the age of twenty, he discovered that the aphis can reproduce for several generations without mating, and that animals other than the "polyp" (hydra) can regenerate themselves. He treated these and other matters in his Traité d'insectologie (1745). When his eyesight became severely weakened from microscopic work, he turned to botany and philosophy. In Recherches sur l'usage des feuilles dans les plantes (1754), he outlined a vitalistic concept of plant behavior in relation to physical environment. In the Essai de psychologie (1754) and the Essai analytique sur les facultés de l'âme (1760), he...