The foundations of economic systems have long been a major concern for Duncan Foley (*1942). One core project throughout his career has been to explain how “the aggregate system [for instance, the economy] stays together” (Colander et al. 2004, 204). In the context of contemporary economics, this means thinking about how to articulate the behavior of individual agents at the micro-level such that it provides proper foundations for macro-phenomena (see also Colander et al. 2004, 23). Foley has approached this question from multiple perspectives, thereby questioning the common but simplified perspective all too common in current equilibrium models (e.g., Farmer and Foley 2009). Foley was educated at Swarthmore College and Yale University where he began his work under the supervision of Herbert Scarf and James Tobin, taking an approach that has often been labeled “mainstream economics.” Unsatisfied with this mainstream approach of equilibrium and utility maximization under constraints, Foley eventually moved to more heterodox perspectives, becoming professor at Barnard College and subsequently Leo Model Professor of Economics at the New School for Social Research in 1999 where he has stayed until his retirement in 2022.