Though Karl Popper’s differentiation between science and pseudo-science was written during the 20th century, his argument is rooted in the patterns of the scientific process during the Scientific Revolution. While simple observation and contemplation were considered reliable methods of science prior to the revolution, empirical evidence and a general atmosphere of skepticism dominated the theories of the Scientific Revolution. It is this shift in process that strengthens the credibility and impact of the discoveries made in the natural sciences during the revolution.

Aristotle produced a significant volume of scientific concepts with his introduction of the cosmos as a division between the quintessential heavens and the sub-lunar realm. Furthermore, he held that the Earth was the center of the solar system and that all matter fell into one of four categories. Though his ideas were widely accepted, they were based only in observation and philosophy. When Copernicus, Kepler, and Galileo offered their differing theories, simple observation and reasoning were not enough to convince the greater population of philosophers that the Aristotelian theories were flawed. The technological developments these scientists had modified to telescopes allowed them to record observations and patterns more intricately. They could support and report their findings in greater detail. It was the need to prove the validity of their theories to the community that ushered in the new empirical attitude of the revolution.

Another similarity between Popper’s philosophy and the empiricism of the sixteenth and seventeenth centuries was the focus on natural science rather than what would be considered pseudo-science as of the twentieth century. The greatest accomplishments of the Scientific Revolution were in the area of biology (the circulation of blood), chemistry (the ideal gas law), and physics (theory of gravity and movement of celestial bodies). These are all considered testable, “hard” sciences that can be supported empirically and are refutable. The work of behaviorists and astrologists, those who studied what would be considered pseudo- science by Popper, was not as greatly renowned or celebrated as the other sciences. They are not the accomplishments one thinks of as defining the Scientific Revolution.

The differentiation between science and pseudo-science and the necessity of empirical evidence are themes that existed in the scientific community prior to Popper assigning a definition.