Six at the beginning means:
Law is the beginning of education. Youth in its inexperience is inclined at first to take everything carelessly and playfully. It must be shown the seriousness of life. A certain measure of taking oneself in hand, brought about by strict discipline, is a good thing. He who plays with life never amounts to anything. However, discipline should not degenerate into drill. Continuous drill has a humiliating effect and cripples a man's powers.