Claude Bernard (1813-1878) was a French physiologist. Milieu interieur is the key process with which Bernard is associated. He wrote, "La fixite du milieu interieur est la condition d'une vie libre et independante" (The constancy of the internal environment is the condition for a free and independent life). This is still the underlying principle of homeostasis today. He was one of the first to suggest the use of blind experiments to ensure the objectivity of scientific observations. In An Introduction to the Study of Experimental Medicine (1865), Bernard describes what makes a scientific theory good and what makes a scientist important, a true discoverer. Unlike many scientific writers of his time, Bernard writes about his own experiments and thoughts, and uses the first person. The basic principles are: known and unknown, induction and deduction, cause and effect, verification and disproof, determinism and averages, truth versus falsification and discovering versus despising.