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Aristotle's Support On The Theory of Spontaneous Generation
Aristotle explicitly stated his support with spontaneous generation in his book The History of Animals, suggesting that some non-living objects contained a condition that had the power to generate life. This set the foundation of spontaneous generation that would exist for centuries. Spontaneous Generation was the theory that life could arise from certain inanimate matters. It refers to abiogenesis(life arising from non-life objects), and heterogenesis(a form of life emerges from another form). -
Jan Baptist van Helmont
Jan Baptist van Helmont was a a Flemish chemist, physiologist and physician. He conducted several experiments in support of spontaneous generation. For example, he showed that a willow tree grew in size after five years, while the soil the willow tree supposedly gained its mass from did not decrease significantly in matter. -
Francesco Redi
Redi was the first to conduct a crucial experiment where he laid out two jars of rotten meat, one with the lid opened, another sealed. Maggots then appeared on the meat in the jar with the open lid, but not in the sealed jar. He showed that maggots didn’t arise from decaying meat, but from adult flies that laid their eggs directly onto the meat. Although, many argued that sealing the inanimate objects would interfere with its condition to generate life, resulting in unconclusiveness. -
John Needham
conducted a series of experiments with boiled broths to test out the theory of spontaneous generation. He originally believed that any living organisms would be killed when the substance is boiled. However, even after sealing the container, life still continued to arise from the broth. To Needham, he then came upon the conclusion that spontaneous generation can still occur even when the inanimate matter is boiling. -
Lazzaro Spallanzani
Spallanzani hypothesized that in Needham’s experiment, the substance was somehow contaminated. Spallanzani then modified Needham’s experiment by placing the boiling broth in a sealed container with the ability for air to partially evacuate. His experiment successfully prevented any life to appear in the broth. However, the believers of spontaneous generation stated that Spallanzani only proved that spontaneous generation could not occur without air. -
Louis Pasteur
Pasteur boiled the broth in a swan flask, he heated the neck of the flask and bent it into an “S” shape. This allowed air to freely travel through the flask, but it prevented the organisms carried by the air to travel upward through the neck into the flask. After the testing days, Pasteur showed that no living things arose from the broth. He then broke the neck of the flask, then did life start to appear in the substance. Pasteur concluded the argument of spontaneous generation.
