"practical" man, taking his word that he is practical and that the trained man is a fool, and "theoretical." Because the word theoretical is used in an awesome manner it is thought to mean something dreadful. Barnum once made a statement that the people like to be humbugged.
Theory is a plain statement of a law that has been proven. Hypothesis is an idea advanced as a theory. The man who takes a thorough engineering course studies the theories underlying his work and thereby obtains a practical understanding of it. In engineering schools a large part of the instruction consists in a study of the work done by engineers and contractors in many parts of the world and during all the centuries. When a young fellow who has conscientiously pursued his engineering studies graduates, it does not take him long to acquire a first-hand practical knowledge of his work and to this he adds a knowledge of what other men have done. It is plain to see, therefore, that the theoretically trained man is the practical man.
The man who has no school training in the underlying theory of his work and merely learns by seeing, without doing much, if any, reading, or without doing any reading under proper guidance, has only his own experience to guide him. He is practical to the extent that he has "picked up knowledge" by doing. Not being a student he knows little of what other men have done, except
