Section 4. The commissioner of youth services shall establish rules, regulations, and by-laws for the government of each institution and shall see that its affairs are conducted according to law and to such rules, regulations, and by-laws; but the purpose thereof and of all education, employment, training, discipline, recreation and other activities carried on in the institutions shall be to restore and build up the self-respect and self-reliance of the children lodged therein and to qualify them for good citizenship and honorable employment.