Our ordinary concept of causality is—as David Hume wisely underscored—the concept in which an event or change produces another event or change. This production is the central core of causation, and the objective component of it Hume analyzed as constant conjunction. As is well known, Hume emphasized that our notion of production or causation has a subjective component, namely, the illusion of a certain necessity in the connection between cause and effect. Typically, the critique of Hume has centered on his attack upon, and on his theses about, necessity. But the core idea of production has been generally kept out of the dialectical stage. Here I will put necessity aside and bring this very idea of production to the center of the stage. I propose to explore the most general logical and ontological features of production. The most intriguing feature is the deep connection between production and energy. But as it will become apparent from the ensuing discussion, that deep connection is mediated by a more general concept of world-orderliness that I shall dub causity. Thus, the general principles here formulated belong to the philosophical foundations of thermodynamics.