Preformationism—one of the dominant scientific theories of the 18th century—is the belief that a tiny tree is hidden inside every seed, and a tiny person curled up inside every sperm. Via Wikipedia:
In the history of biology, preformationism (or preformism) is the idea that organisms develop from miniature versions of themselves. Instead of assembly from parts, preformationists believe that the form of living things exist, in real terms, prior to their development. It suggests that all organisms were created at the same time, and that succeeding generations grow from homunculi that have existed since the beginning of creation.
Pythagoras is one of the earliest thinkers credited with ideas about the origin of form in the biological production of offspring. It is said that he originated “spermism”, the doctrine that fathers contribute the essential characteristics of their offspring while mothers contribute only a material substrate.
The groundbreaking scientific insights provided by Galileo and Descartes seemed to support preformationism.
