In [the soul] one part naturally rules, and the other is subject, and the virtue of the ruler we maintain to be different from that of the subject; the one being the virtue of the rational, and the other of the irrational part. Now, it is obvious that the same principle applies generally, and therefore almost all things rule and are ruled according to nature.
Thanks to my fortunate idea of introducing the relativity principle into physics, you (and others) now enormously overrate my scientific abilities, to the point where this makes me quite uncomfortable.
Rhythm and melody enter into the soul of the well-instructed youth and produce there a certain mental harmony hardly obtainable in any other way. . . . thus music, too, is concerned with the principles of love in their application to harmony and rhythm.
There are some with whom we may study in common, but we shall find them unable to go along with us to principles. Perhaps we may go on with them to principles, but we shall find them unable to get established in those along with us. Or if we may get so established along with them, we shall find them unable to weigh occurring events along with us.