In ‘Aristotle on the Stages of Cognitive Development’, Thomas Kjeller Johansen examines Aristotle’s contributions to our thinking about concepts from a different perspective, namely in connection to Aristotle’s psychology. He revisits Aristotle’s account of how we acquire universal concepts mainly on the basis of Metaphysics A.1, Posterior Analytics 1.31 and 2.19, and the De Anima. The chapter begins by articulating the following puzzle. On the one hand, Aristotle points out (An. Post. 1.31, 2.19) that we perceive the universal in the particular. On the other, he suggests (Metaph. A.1) that it is only when we have craft and science that we grasp the universal, while perception, memory, and experience all are concerned with the particular. Building on the widespread view that, according to Aristotle, the universal grasped in craft and science is the universal cause, Johansen argues that we should understand perception, memory, and experience teleologically, as stages in the ordering of perceptual information that allows this causal concept to emerge.

The Introduction sets the scene by addressing first the problems involved with translating the term technê and related issues with circumscribing the Greek concept. The social context of craft and craftsmen is briefly discussed. Criteria for technê are outlined, with the importance of the Hippocratic writings for Plato and Aristotle highlighted. The central role of technê as a model of knowledge is introduced, and its applications to a range of disciplines, including ethics, politics and cosmology.

This chapter discusses the use of technê to characterize the creator god in Plato’s Timaeus. Timaeus explains how a divine craftsman, the Demiurge, made the whole cosmos as a living being. He created the heavenly bodies, but left the creation of human and other mortal beings to these ‘lesser’ gods. But if the Demiurge was the best of all craftsmen, seeking to make the finest cosmos possible, why did he not make the mortal beings too? Having outlined Plato’s conception of craft, Johansen explains how this problem, which he calls the ‘technodicy’, arises for Timaeus, contrasting it with the classical theodicy. The Demiurge’s creation is limited by his craft. Timaeus therefore assigns another craft to the lesser gods to produce mortal beings. However, even this craft prevents the lesser gods from directly producing non-human animals, and so the problem is reiterated. The issue is sought to be resolved by making humans themselves responsible for their own reincarnation as lower animals. Timaeus’ position is comparable to the view in Laws X: the lesser gods, consistent with their role as craftsmen, have overall responsibility for the organization of lower kinds of living being, without causing any particular beings to belong to particular kinds.

Johansen examines the role of internal heat in the theories of nutrition and animal generation in Plato’s Timaeus. There, Plato does not ascribe the status of being besouled to all beings which engage in nutrition, but to beings with perceptive faculties. This raises questions as to the status of nutrition in the explanation of life and besouled beings.

A teleological explanation is an explanation in terms of an end or a purpose. So saying that ‘X came about for the sake of Y’ is a teleological account of X. It is a striking feature of ancient Greek philosophy that many thinkers accepted that the world should be explained in this way. However, before Aristotle, teleological explanations of the cosmos were generally based on the idea that it had been created by a divine intelligence. If an intelligent power made the world, then it makes sense that it did so with a purpose in mind, so grasping this purpose will help us understand the world. This is the pattern of teleological explanation that we find in the Presocratics and in Plato. However, with Aristotle teleology underwent a change: instead of thinking that the ends were explanatory because a mind had sought to bring them about, Aristotle took the ends to operate in natural beings independently of the efforts of any creative intelligence. Indeed, he thought that his predecessors had failed to understand what was distinctive of nature, namely, that its ends work from the inside of natural beings themselves.