Recent article by the very excellent Paul Lewis in History of Political Economy Volume 48, Issue 1. Abstract: This article identifies the sources on which Friedrich Hayek drew in order to develop his understanding of the notion of emergence. It is widely acknowledged that the notion of emergence plays a significant role in Hayek’s analyses of both the mind and the market. In Hayek’s account, the key capacities of the human mind—such as its capacity to enable people to perceive the world around them and to form plans about how to act—are emergent properties of the structured array of neurons found in the human brain. Analogously, Hayek’s analysis of the market portrays the coordinative powers of the price mechanism as an emergent property of the social system that is formed when people’s (inter)actions are governed by a set of norms that includes both the formal rules of property and tort and contract law, and also informal norms of honesty and promise keeping. However, while several scholars have identified the importance of the notion of emergence in Hayek’s thought, none have explored systematically and in detail the sources from which he acquired his knowledge of the concept. This article remedies that omission by examining the history of Hayek’s use of the concept of emergence and identifying the sources through which notions of emergence and “emergent properties” entered his thinking. It is argued that the three main sources of influence are as follows: the ideas of the German psychologist Wilhelm Wundt; the work of members of the gestalt school of psychology; and the writings of the organicist biologists Joseph Woodger and Ludwig von Bertalanffy. The significance of the article’s findings for those interested in the development of Hayek’s economics is also discussed.