All About Science Green and blue chemistry symbols - All About Science Banner

Louis Pasteur

QUESTION: Who was Louis Pasteur?


Louis Pasteur was born in 1822 in Dole, France. His discovery that most infectious diseases are caused by germs, also known as the "germ theory of disease," is one of the most important in medical history. His work became the foundation for the science of microbiology, and a cornerstone of modern medicine.

As Pasteur was growing up, his teachers thought that Louis was not fit for advanced studies, and felt he should carry on the work of his father as a tanner of leather. However, one teacher realized that Pasteur was bright and found he was slow, yet methodical and persistent.

Eventually Pasteur was schooled in Paris by some of the best teachers. He soon became a professor at different schools and took on various projects. Throughout his life, one major discovery led to the next discovery in a natural progression of research.

Pasteur discovered that weakened forms of microbes could be used as an immunization against more virulent forms of microbes. As a pioneer of immunology, Pasteur lived at a time when thousands of people died each year of rabies. He spent years working on a vaccine. Just as he was about to experiment on himself, a nine-year-old boy, Joseph Meister, was bitten by a rabid dog. The boy's mother begged Pasteur to experiment on her son. Pasteur injected the boy for 10 days -- and the boy lived. Decades later, of all things Pasteur could have etched on his tombstone, he asked for 3 words, "Joseph Meister lived." Pasteur believed our greatest legacy to be those who live eternally because of our effort.

Louis Pasteur was first to describe the scientific basis of fermentation. Shunned by doctors and fellow scientists, Pasteur documented in great detail the method that allowed sugar to turn into alcohol, by way of yeast. Pasteur showed the yeast to be an organism which did not require oxygen for fermentation to occur. This showed Justus Von Liebig who had maintained the fermentation was purely chemical, to have been mistaken. Pasteur demonstrated that mild heating applied after fermentation would kill the microorganisms and prevent souring.

Even though controversial, Louis took on the question of whether spontaneous generation (life from non-life) or biogenesis (life from life) was true. He decided to repeat the experiments of Redi and Spellanzani and create his own to answer objections of critics. With a specially constructed bent flask, Pasteur demonstrated conclusively that decay was produced by air-borne microorganisms. This refuted the doctrine of spontaneous generation. When he was asked if he believed in evolution, he said, "no." His studies showed that life only comes from life and that life comes from parents similar to themselves. Pasteur questioned the theory of evolution, because Darwin did not base his ideas on experimental proof. Louis said, "Do not put forward anything that you cannot prove by experimentation."

Rather than destroying his belief in God, Pasteur's brilliant discoveries made him humble as he contemplated the marvels of divine creation. He argued that the notion of spontaneous generation (like materialism) threatens the very concept of God the Creator.

Pasteur also discovered the parasite responsible for killing silkworms, and saved the French silk industry by recommending that all infected worms and mulberries be destroyed. Pasteur's work with silkworm parasites and air-borne germs led him to propose the germ theory of disease. He pressed doctors to disinfect their instruments by boiling and steaming. He found that septicemia was caused by an anaerobic bacterium. He urged surgeons to use clean instruments, wash their hands, and disinfect their gauze and bandages.

Louis Pasteur may be most well known for the invention of pasteurization, a process by which harmful microbes in perishable food products are destroyed using heat, but leaving the original product unharmed.

Pasteur was a thorough, highly intuitive researcher who always considered the wider ramifications to his work. While he revered science, Pasteur always believed that there were spiritual values that transcend it. Pasteur died in 1895, but his phenomenal contributions to microbiology and medicine can still be witnessed today.

Learn More About the Origin of Life!

Copyright © 2002-2021, All Rights Reserved