Economists have avoided issues of time, knowledge and uncertainty, yet we live in an unremittingly chaotic, unpredictable universe in which all anticipations are bounded. The theory of planning horizons is a formalization of Herbert Simon's notion of rational limits: horizon effects are an ordinal shift of our ranges of vision and understanding with real economic effects, framing a case for generalized complementarity and the efficiency of cooperation. The key question for social organization becomes horizonal: how to structure economic incentives for broader planning perspectives. Competitive systems have failed us in the presence of complementarity! Indeed, competition has spawned a dangerously myopic culture reeling toward self-destruction, as evidenced by widespread ethical failures and ecological losses. This book offers a detailed description of what went wrong in economics along with the foundations for a new Horizonal Economics of complementarity, cooperation and social cohesion. With economic incentives structured to favor larger perspectives and greater social conscience, all systems will serve our needs more effectively and to a happier outcome, socially and culturally.