If all matters pertaining to temperament, will, and understanding proceed according to ritual, they will be ordered and successful; if not they will be perverse and violent or slovenly and rude. If matters pertaining to food and drink, dress, domicile, and living habits proceed according to ritual, they will be harmonious and well regulated; if not they will end in missteps, excesses, and sickness. If matters pertaining to deportment, attitude, manner of movement, and walk proceed according to ritual, they will be refined; if not they will be arrogant and uncouth, common and countrified. Therefore a man without ritual cannot live; an undertaking without ritual cannot come to completion; a state without ritual cannot attain peace.
Ritual is the means by which to rectify yourself; the teacher is the means by which ritual is rectified. If you are without ritual, how can you rectify yourself? If you have no teacher, how can you understand the fitness of ritual?