In engineering school, we have laboratory classes so that we can also learn from our own experience. Is the iron crystal structure really cubic? We might be given a chance to perform X-ray diffraction in a lab and be required to work out the angles between the planes of the crystal from the dot patterns on an X-ray detector. 

Way back in the 1970s, my sophomore metallurgy class was broken up into small groups and given lead and tin. Each group was responsible to weigh, mix and melt a different ratio of the two elements. Then we had to pour the molten mixture into a glass beaker that was sitting in a thermos surrounded by water. By monitoring the rate of temperature change in the water due to the heat released by the cooling and solidifying lead-tin mixture, we were able to determine the starting and ending points of the solidification temperature range. Through this work, we gained a direct understanding of how phase diagrams are researched.

The best teaching uses both “revealed knowledge” provided by “authorities” in their branches of knowledge and direct experience so that we can “see for ourselves.” This is the foundation of using theory and practice together with each bolstering or reducing our confidence in the other, based on the agreement or lack thereof between the two types of knowledge.

The length of a course of study is limited, so we can never repeat the entire history of the development of any branch of knowledge that is developed enough to have an actual university department. The curriculum developers must pick and choose which topics will be treated as “revealed truths” and which will require the students to “prove it to themselves.” In life, as we move on from the exercises that we do in school, which have known outcomes, to confronting real-life issues that may not have any true solutions, the most intellectually successful of us will generally be forced to re-evaluate at least some of what we “knew.” 

It’s not necessarily that what we knew was outright wrong. Usually, we run into problems when we try to use some bit of knowledge in a situation where it doesn’t apply. More thoughts next time.