The complexity approach to economics largely originated from the Santa Fe Perspective : the view of a group of scientists working in the Economics Program (19882004) at the Santa Fe Institute for the Study of Complex Systems (hereafter SFI).(1) This paper tells the story of the Santa Fe Perspective, traces its relation with other ideas that emerged at SFI in this seminal period, and concludes with some reflections on the current state of complexity theory in economics. I divide the life of the Economics Program in three periods roughly corresponding to the three Workshops (1987, 1996, 2001) dedicated to The Economy as an Evolving Complex System. Each of them reflects a stage in the development of the Santa Fe Perspective, characterized by a particular constellation of attitudes, ideas and objectives: the weakly heterodox, the strongly heterodox and the synthesis periods. These labels reflect the prevailing orientation towards neoclassical economics which seems to be on the one hand, a core concern for the directors of the Economics Program, and, on the other hand, a central issue for the relevance of complexity to economic theory.