A behavior is a primitive here, so it cannot be defined, though examples can be given of it. A behavior has a subject (what behaves), which is an internal parameter of it (ontologically dependent on it), and has (or can have) other parameters as well: a space where, and a time when, it occurs; something it applies to. The same behavior can recur; it can expand and contract; and it can change. To the extent that it does not change, it is steady; to the extent that it changes, it plays. And it can learn from its play: so evolve as to face difficulties that have arisen, but also to get into more difficulties (helplessness, and self-destructiveness, can be learned). Behaviors and their subjects can interact, causing change and play in some or all of them, which can be productive for one while it is unproductive, or even counterproductive, for another. A subject that was absolutely steady would be an object. But there can be no objects: every subject eventually changes, and plays; it can (indeed, will) even return from the dead. What there is is always a compromise between play and objectivity; and the amount of objectivity that is present allows for the practice of scientific disciplines. Whose predictions hold until they no longer do: Kant taught us that we live in a world of phenomena, which may be well-behaved within a limited context (and for a while) but are bound to explode if we try to take a universal point of view on them. A more contemporary jargon would reformulate Kant’s antinomies in terms of chaos theory. In a chaotic world, play is the engine of survival, and there is a constant struggle for who gets to play, and to survive.