"Nothing is so conducive to a right appreciaton of the truth as a right appreciation of the error by which it is surrounded. The successful investigator must bring to test statements and conceptions which have been too long accepted on faith, habit, or good-nature. He must look boldly behind certain large words which are now too often the shelter of ignorance, and he must satisfy himself whether they have any definite value or not. When it is seen how much our current language really signifies, and when all technicalities, which took their rise in old and false methods, have been swept out of sight, we shall feel, perhaps, a little bare, but at any rate we shall have open field for our new researches."