Charles Bonnet

Charles Bonnet was a Genevan naturalist and philosophical writer. He is responsible for coining the term phyllotaxis to describe the arrangement of leaves on a plant. Bonnet was from a French family driven into the Geneva region by the religious persecution in the 16th century. Bonnet seems never to have left the Geneva region, does not appear to have taken any part in public affairs except for the period between 1752 and 1768, during which he was a member of the council of the republic; the last twenty five years of his life he spent in the country, at Genthod, near Geneva, where he died after a long and painful illness on 20 May 1793. His wife was a lady of the family of De la Rive, they had no children, but Madame Bonnet's nephew, the celebrated Horace-Bénédict de Saussure, was brought up as their son. He made law his profession; the account of the ant-lion in Noël-Antoine Pluche's Spectacle de la nature, which he read in his sixteenth year, turned his attention to insect life. He procured RAF de Réaumur's work on insects, with the help of live specimens succeeded in adding many observations to those of Réaumur and Pluche.

In 1740, Bonnet communicated to the Academy of Sciences a paper containing a series of experiments establishing what is now termed parthenogenesis in aphids or tree-lice, which obtained for him the honour of being admitted a corresponding member of the academy. During that year he had been in correspondence with his uncle Abraham Trembley who had discovered the hydra; this little creature became the hit of all the salons across Europe once philosophers and natural scientists saw its amazing regenerative capabilities. In 1741, Bonnet began to study reproduction by fusion and the regeneration of lost parts in the freshwater hydra and other animals. In 1743, he was admitted a fellow of the Royal Society. In 1753, he was elected a foreign member of the Royal Swedish Academy of Sciences, on 15 December 1769 a foreign member of the Royal Danish Academy of Sciences and Letters, his first published work appeared in 1745, entitled Traité d'insectologie, in which were collected his various discoveries regarding insects, along with a preface on the development of germs and the scale of organized beings.

Botany the leaves of plants, next attracted his attention. In this book, he observes that gas bubbles form on plant leaves that have been submerged in water, indicating gas exchange, but Bonnet's eyesight, which threatened to fail altogether, caused him to turn to philosophy. In 1754 his Essai de psychologie was published anonymously in London; this was followed by the Essai analytique sur les facultés de l'âme, in which he develops his views regarding the physiological conditions of mental activity. He returned to physical science, but to the speculative side of it, in his Considerations sur les corps organisées, designed to refute the theory of epigenesis, to explain and defend the doctrine of pre-existent germs. In his Contemplation de la nature, one of his most popular and delightful works, he sets forth, in eloquent language, the theory that all the beings in nature form a gradual scale rising from lowest to highest, without any break in its continuity, his last important work was the Palingénésie philosophique.

Bonnet's complete works appeared at Neuchâtel in 1779–1783 revised by himself. In 1760 he described a condition now called Charles Bonnet Syndrome, in which vivid, complex visual hallucinations occur in psychologically normal people. Most people affected are elderly with visual impairments, however the phenomenon does not occur only in the elderly or in those with visual impairments. Bonnet's philosophical system may be outlined. Man is a compound of two distinct substances and body, the one immaterial and the other material. All knowledge originates in sensations. A nerve once set in motion by a particular object tends to reproduce that motion; the sensation accompanying this increased flexibility in the nerve is, according to Bonnet, the condition of memory. When reflection—that is, the active element in mind—is applied to the acquisition and combination of sensations, those abstract

Mario Szegedy

Mario Szegedy is a Hungarian-American computer scientist, professor of computer science at Rutgers University. He received his Ph. D. in computer science in 1989 from the University of Chicago. He held a Lady Davis Postdoctoral Fellowship at the Hebrew University, Jerusalem, a postdoc at the University of Chicago, 1991–92, a postdoc at Bell Laboratories. Szegedy's research areas include computational complexity quantum computing, he was awarded the Gödel Prize twice, in 2001 and 2005, for his work on probabilistically checkable proofs and on the space complexity of approximating the frequency moments in streamed data. He has two daughters. Home page