Final answer:
Louis Pasteur is credited with conclusively disproving the theory of spontaneous generation, demonstrating through his swan-neck flask experiments that life arises from life, a concept known as biogenesis.
Step-by-step explanation:
The individual credited with definitively refuting the theory of spontaneous generation was the French chemist Louis Pasteur. His work in the mid-19th century challenged the idea that life could emerge from nonliving matter without the presence of any existing life. Pasteur's famous experiment involved the use of swan-neck flasks containing broth, which, after being boiled to kill all microbes, remained free of microbial life until the flasks were opened to air—demonstrating that life did not spontaneously generate in the broth but was introduced via airborne microorganisms.
Previous experiments by Francesco Redi involving raw meat and maggots, and the work of other scientists both for and against spontaneous generation, paved the way for Pasteur's conclusive proofs.