Spontaneous Generation Doctrine (or Abiogenesis)
Men of ancient times (Thales, 624-548 B.C.; Anaximander, 611-547 B.C.; Anaximenes, 588-524 B.C.; Empedocles, 504-433 B.C.; Aristotle, 384-322 B.C.; Epicurus, 341-270 B.C.; and Socretius 99-55 B.C.) knew nothing of microorganisms, of evolution, or of the fact that only living things could beget living things. They believed that all living organisms could spring forth spontaneously from non­living matter. This belief has been referred to as Doctrine of Spontaneous Generation or Abiogenesis (Gr. a = not; bios = life; genesis = origin).

They believed that frogs, snakes and mice could be born of moist soil, that flies could emerge from manure, and that maggots could arise from decaying corpses. The idea of spontaneous generation was supported even 2000 years later. Van Helmont (1577-1644) devised a method for manufacturing mice. He recommended putting some wheat grains with soiled linen and cheese into an appropriate receptacle and leaving it undisturbed for a time in an attic or stable. Mice would then appear. However, the idea of spontaneous generation continued until the mid-19th century with great oppositions against it.