Be not a slave of words.

Carlyle’s injunction warns against letting language—labels, slogans, fashionable phrases, or inherited formulas—do one’s thinking. To be a “slave of words” is to mistake verbal categories for realities, to substitute rhetoric for judgment, and to allow public catchwords to govern conscience and action. The line fits Carlyle’s broader critique of cant and “shams”: he repeatedly urges readers to look past eloquence, abstractions, and secondhand opinions to the underlying facts, moral duties, and lived experience. In this sense, the quote champions intellectual independence and moral seriousness: use words as tools for truth, not as masters that dictate what is real or right.