David Charles presents a major study of Aristotle's views on meaning, essence, and necessity. Aristotle's discussions of these interconnected topics are central to his account of thought and language, his metaphysics, and his study of biology. They are also of continuing philosophical importance, with considerable relevance for modern debates on these issues. Charles aims, on the basis of a careful and detailed reading of Aristotle's texts, to reach a clear understanding of his distinctive claims and arguments, and to assess their value and significance. He argues that Aristotle's actual account is distinct from the one often described and attacked as 'Aristotelian essentialism'. Indeed, in Charles's view, it enjoys considerable advantages over more recent attempts to formulate and defend essentialist theses.