The Philosophy of Grammar, a radical innovation in linguistics research when it was first published, is now a standard reference work and all students in the field should be familiar with it. The topics covered are living grammar, systemic grammar, parts of speech, the three ranks, junction and nexus, nexus-substantives, subject and predicate, object, case, number, person, sex and gender, comparison, time and tense, direct and indirect speech, classification of utterances, moods, and negation. Believing that a fixed terminology could be a hindrance to real understanding, Mr. Jesperson introduced new terms "neither very numerous nor very difficult" and discarded some he felt were outmoded. "The great merit of this work," commented the reviewer for The Times Literary Supplement, "seems to be in the thorough shaking-up which it gives to a great many venerated idols."