Jacques Loeb, a German-born biologist who became one of the most famous scientists in America when Mark Twain wrote an essay in 1910 titled, “Dr. Loeb’s Incredible Discovery”, was born on this date in 1859. Loeb’s “incredible discovery” was that he could stimulate parthenogenesis — the development of eggs into embryos without the presence of sperm — in sea urchins through slight chemical modifications of the water in which their eggs were kept. The New York Times reported a “consensus of opinion among biologists” that Dr. Loeb was “a man of lively imagination” more than “an inerrant investigator of natural phenomena,” but Twain’s essay savaged the very notion of “consensus of opinion.” Loeb had come to America in 1891, and became a department head at the Rockefeller Institute for Medical Research in 1910. He spent his summers working in the Woods Hole marine laboratory in Massachusetts. He was best known for his experiments and theories on animal tropism (reflexive response to chemical or sensory stimuli), work that became a foundation of psychological behaviorism. Sinclair Lewis used Loeb as the model for his visionary scientist character, Max Gottlieb, in his Pulitzer Prize-winning novel, Arrowsmith (1925).
“I think one day — by some future generation — [my ideas] may be elaborated into a mathematical theory of human behavior.” —Jacques Loeb, letter to Louis Brandeis, 1921