"Strategic Entrepreneurship Journal, forthcoming""This version: 5 June 2008"This paper reviews and critiques the "opportunity discovery" approach to entrepreneurship and argues that entrepreneurship can be more thoroughly grounded, and more closely linked to more general problems of economic organization, by adopting the Cantillon-Knight-Mises understanding of entrepreneurship as judgment. I begin by distinguishing among occupational, structural, and functional approaches to entrepreneurship and distinguishing among two influential interpretations of the entrepreneurial function, discovery and judgment. I turn next to the contemporary literature on opportunity identification and argue that this literature misinterprets Kirzner's instrume...