Born Mar. 13, 1720, in Geneva; died May 20, 1793, in Geneva. Swiss naturalist and philosopher.
In 1745, in his Treatise on Insects, Bonnet described an-thropoda, polyps, and worms and related new data on the life and instincts of insects. He was one of the first to describe parthenogenesis in plant lice. He observed the process of regeneration in worms, hydras, starfish, snails, crayfish, and amphibians; he expressed the correct hypothesis that regeneration is, in some species of animals, one of the forms of adaptation to the hostile influences of the external environment.
In 1754, in his work An Investigation of the Role of Leaves in Plants, Bonnet tried to explain the physiological functions of the leaf and the movement of plant fluids. In his works Discourse on Organized Bodies (volumes 1–2, 1762), Contemplation of Nature (volumes 1–2, 1764), and Philosophical Palingenesis (volumes 1–2, 1769), Bonnet emerged as a resolute opponent of the theory of spontaneous generation of microorganisms and as a supporter of the theory of preformation. Bonnet was among the authors of studies on the “ladder of beings,” according to which all inorganic bodies and living organisms are distributed in a certain order, from the simplest to the most complex, including man, and extending further to include supernatural beings—angels, archangels, and so on. In questions of epis-temology, Bonnet considered experience and empirics very important, although he also pointed out that human capabilities of perceiving the world are limited.