The Greeks did not separate language from reason. Their word logos meant both 'speech' and 'rational thought', encoding the assumption that clear thinking and clear speaking were the same activity. When Aristotle formalised the study of valid reasoning, he named it logike — the art of logos — and the discipline of logic was born. Logical entered English in the 16th century through Latin logicalis, carrying Aristotle's legacy in its syllables. The word distinguished itself from logic (the noun) by adding the -ical suffix, a Latin-derived ending that English uses prolifically (historical, political, musical, classical). In everyday use, logical has softened from its strict philosophical meaning. Aristotle meant something precise: an argument where the conclusion necessarily follows from the premises. Modern speakers use logical more loosely — 'that seems logical' often means 'that makes sense' rather than 'that follows by syllogistic necessity'. The root logos generated one of English's largest word families. The suffix -logy ('study of') alone accounts for hundreds of terms: biology, geology, psychology, etymology itself. Dialogue ('through words'), monologue ('single speech'), analogy ('proportion'), and prologue ('before the word') all contain it. Logarithm combines logos with arithmos ('number'). Few roots in any language have been as generative, and fewer still carry such a weight of intellectual history.