# Louis Pasteur French chemist and microbiologist (1822-1895). One of the founders of microbiology, immunology, and the germ theory of disease. His swan-neck flask experiments (1859-1864) are the empirical landmark for the **Law of Biogenesis**, *omne vivum ex vivo*, "all life comes from life", which decisively refuted spontaneous generation as it was then understood. ## Major contributions - **Refutation of spontaneous generation (1859-1864).** Pasteur designed sealed and swan-neck flasks to show that microbial growth in sterilized broth requires the introduction of pre-existing microorganisms from the environment. The 1864 public demonstration at the Sorbonne was decisive in the French scientific community. - **Germ theory of disease.** Showed that specific microorganisms cause specific diseases (silkworm disease, anthrax, chicken cholera, rabies). The germ theory transformed medicine, surgery, and public health. - **Pasteurization.** The mild-heat process for preserving wine, beer, and milk that bears his name. - **Vaccination.** Developed attenuated-pathogen vaccines for chicken cholera (1879), anthrax (1881), and rabies (famously administered to Joseph Meister in 1885). - **Stereochemistry.** His early work on the optical activity of tartaric acid (1848) founded stereochemistry and showed that chirality is a fundamental feature of biological molecules. ## Pasteur's religious posture Pasteur was a practicing Catholic. His public statements indicate that he saw no conflict between his scientific work and Christian faith; he is widely (though not always reliably) quoted to the effect that "a little science estranges from God; much science returns to Him." Whether or not the specific quotation is authentic, his life and correspondence support a settled theistic posture rare among 19th-century scientific elites. ## The 1864 Sorbonne lecture After demonstrating the swan-neck flask experiment, Pasteur declared: > Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment. This statement (Sorbonne, 7 April 1864) became the public marker of the death of spontaneous generation as a serious scientific position. ## Mentions in [Abiogenesis Under the Microscope](/codex/abiogenesis-under-the-microscope/) The ris3n.com paper (2025) opens its Part I with Pasteur as the foundational empirical witness for the Law of Biogenesis. The 1864 Sorbonne quotation is reproduced in full. The paper is careful to distinguish Pasteur's refutation of *spontaneous generation* (the old idea that life pops up from non-living matter under ordinary conditions) from the modern *abiogenesis* hypothesis (a one-time event under hypothetically different ancient conditions), but argues that Pasteur's empirical landmark places the burden of proof on anyone claiming a one-time exception. Pasteur's work supplies P1 of the [Biogenesis Argument](/codex/biogenesis-argument/). See [Law of Biogenesis](/codex/law-of-biogenesis/). ## See also - [Law of Biogenesis](/codex/law-of-biogenesis/), primary concept hub for *omne vivum ex vivo* - [Biogenesis Argument](/codex/biogenesis-argument/), syllogism built on Pasteur's empirical work - [Abiogenesis](/codex/abiogenesis/), the modern hypothesis Pasteur's work indirectly bears on - Abiogenesis Under the Microscope (ris3n), primary source for his role in this codex