I read this book in the 1960's. In the 60's I got an associates degree in medical laboratory technology and went on to seek a Bachelor's degree in Chemistry but ended up getting a Bachelor of Arts degree in political science. You might say that I grew up learning knowledge by applying the scientific method. The scientific method has four steps in it. Observation utilizing the five senses of sight, hearing, touch, taste, and smell.
Observation is used to gather data.
Step 2 is called hypothesis or taking a guess of why something works the way it does. Step three is extrapolation and theorizing how the hypothesis would work in unobserved situations. Step 4 is observing to confirm or refute extrapolations or corroboration. If the extrapolation is observed to be true, the extrapolation is elevated to the status of theory or even a law. If the extrapolation is refuted by observation, it is rejected as unworkable and not true or false theory.