Now, in these same sixteenth, seventeenth and eighteenth centuries, in which we have seen science recovering itself after having been so long tongue-tied by authority, a remarkably similar process goes on in the art of music. If, as we did in considering the progress of science, we now place ourselves at a standpoint from which we can precisely estimate that extension of man's personal relation towards the unknown during these centuries, which resulted in modern music, we are met with a chain of strikingly similar facts and causes. The Greek music quite parallels Greek physical science. We have seen how, in the latter, a Greek philosopher would start off with a well-sounding proposition that all things originated in moisture, or in fire, or in air, and we have seen how, instead of attacking moisture, fire and air, and of observing and classifying all the physical facts connected with them, the philosopher after awhile presents us with an amazing superstructure of pure speculation wholly disconnected from facts of any kind, physical or otherwise. Greek music offers us precisely the same net outcome. It was enthusiastically studied, there were multitudes of performers upon the lyre, the flute, and so on, it was a part of common education, and the loftiest souls exerted their loftiest powers in theorizing upon it. For example, in Plato's _Republic_, Socrates earnestly condemns every innovation upon music. His words are: "For any musical innovation is full of danger to the State.... Damon tells me, and I can quite believe him ... that when modes of music change, the fundamental laws of the State always change with them;" ... (therefore) "our guardians must lay the foundations of their fortress in music." Again, in Book III., during a discussion as to the kind of music to be permitted in our Republic, we have this kind of talk. Socrates asks: "Which are the harmonies expressive of sorrow?" It is replied, they are "the mixed Lydian and the full-toned or bass Lydian." "These must be banished.... Which are the soft or drinking harmonies?" "The Ionian and the Lydian." These, it appears, must also be banished. "Then the Dorian and the Phrygian appear to be the only ones which remain." Socrates "answered; of the harmonies I know nothing; but I want to have one warlike which will sound the word or note which a brave man utters in the hour of danger or stern resolve, or when his cause is failing ... (and he) meets fortune with calmness and endurance; and another to be used by him in times of peace and freedom of action.... These two harmonies I ask you to leave: the strain of necessity and the strain of freedom, the strain of the unfortunate and the strain of the fortunate, the strain of courage and the strain of temperance; these, I say, leave."