A true teacher defends his students against his own personal influences.

Alcott’s remark frames teaching as an ethical discipline of self-restraint. The “personal influences” a teacher must guard against include vanity, dogmatism, ideological imprinting, and the subtle pressure students feel to mirror an admired authority. A “true teacher,” in this view, aims to cultivate the student’s independent judgment and moral agency rather than reproducing the teacher’s personality or opinions. The paradox—defending students against oneself—highlights how power operates in education: even benevolent guidance can become coercive if it eclipses the learner’s own development. The line fits Alcott’s broader transcendentalist emphasis on inner growth and self-reliance.