Inductive Reasoning
When we discover that a certain operation repeated many times always produces the same result we feel justified in concluding that we can announce it as a universal law. After thousands of falling bodies have been measured and always give the same figures, scientists feel that they may state the law that all falling bodies acquire an acceleration of 32.2 feet per second.
This illustrates the inductive method of reasoning. In this system we reason from the specific instance to the general law, from the particular experiment to the universal theory, from the concrete instance to the wide principle.
All modern science is based upon this method—the experimental one. All general theories of any kind today must—to be accepted—be supported by long and careful consideration of all possible and probable circumstances. The theory of evolution as applied to the living things upon the earth is the result of countless observations and experiments.