The Biology Book: From the Origin of Life to Epigenetics, 250 Milestones in the History of Biology (2015)

Scientific Method

Aristotle (384–322 BCE), Francis Bacon (1561–1626), Galileo Galilei (1564–1642), Claude Bernard (1813–1878), Louis Pasteur (1822–1895)


Formulation and fine-tuning of the scientific method has evolved over the ages and is based upon the contributions of many early distinguished scholars including Aristotle, who introduced logical deduction, a “top-down” approach, that is, starting with a theory or hypothesis and then testing that theory; Francis Bacon, the father of the modern scientific method, who in 1620 wrote Novum Organum Scientiarum, which proposed inductive reasoning as the foundation for scientific reasoning, a “bottom-up” approach in which specific observations led to the formulation of a general theory or hypothesis; and Galileo, who advocated experimentation rather than metaphysical explanations. In the mid-nineteenth century, Louis Pasteur elegantly utilized the scientific method when he designed experiments to disprove the theory of spontaneous generation.

In 1865, Claude Bernard, one of the greatest of all scientists, wrote An Introduction to the Study of Experimental Medicine, which he personalized by using his own thoughts and experiments. In this classic book, he examined the importance of the scientist bringing forth new knowledge to society, and he then proceeded to critically analyze what constituted a good scientific theory, the importance of observation rather than reliance on historical authorities and sources, inductive and deductive reasoning, and cause and effect.

When some nonscientists think of theories, such as the theory of evolution, not infrequently they use the term “theory” disparagingly and assume or imply that it imputes an unproven notion or a mere guess or speculation. Scientists, by contrast, use the term “theory” to refer to an explanation, model, or general principle that has been tested and confirmed and that explains or predicts a natural event. The scientific method follows a number of sequential steps and is an approach used to investigate phenomena or acquire new knowledge. Using a series of steps, it is based upon developing and testing a hypothesis that explains a given observation, objectively evaluating the test results obtained, and then accepting, rejecting, or modifying that hypothesis. A theory is broader and more general than a hypothesis and is supported by experimental evidence based on a number of hypotheses that can be tested independently.

SEE ALSO: Refuting Spontaneous Generation (1668), Darwin’s Theory of Natural Selection (1859).

In his 1620 book, Novum Organum (New Method), Francis Bacon proposed a scientific method of inquiry based on inductive reasoning, in which a generalization is built based on incremental data collection. This method was intended to improve upon Aristotle’s deductive reasoning, in which specific facts are deduced from a generalization.