  Aristotelian essentialism is the view that there exist what modern philosophers would treat as natural kinds, for example, human beings, horses and acanthus plants. Individuals belonging to these kinds have essential natures that are definable. These individuals cannot survive a change in essence, but they can survive a change in their accidental properties. There is a difference between dying and dyeing one’s hair. When a human being ceases to be a human being, she dies. By contrast, when her hair is dyed a different color, she survives. In an earlier work, Aristotle distinguishes essence, for example the necessary property of being rational for a human being, from accident, for example, being asleep, and from distinctive properties, those necessary properties that are explained by rationality but are not part of the human essence, for example, the capacity to learn a language (Topics I 5). It is a puzzling feature of the argument of Metaphysics IV 4 that distinctive properties are not explicitly mentioned.