Grau theurer Freund ist alle Theorie
Und grün des Lebens goldener Baum.
Goethe
Everyone realizes the constraint that is placed upon the lives of men by the physical necessities of the world in which we live, and although in one way this constraint is more and more relieved with the progress of the applied sciences, in another way it becomes more and more exacting. It is indeed easier to cross the Atlantic Ocean now than it was in Leif Ericsson's time, but consider the discipline of the shop, and above all consider the rules of machine design! Could even the hardy Norsemen have known anything as uncompromisingly exacting as these? To do things becomes easier and easier, but to learn how to do things becomes more and more difficult.
Every person I have ever talked with, old or young, theorist or practician, student-in-general or specialist in whatever line, has exhibited more or less distinctly a certain attitude of impatience towards the exactions of this or that phase of the precise modes of thought of the physical sciences.
"Da wird der Geist Euch wohl dressiert