Behavior is a sequence of actions. Premackian conditioning occurs when one of those actions permits an animal to engage in more biologically potent positive responses-reinforcement-or forces them to engage in less positive (or negative) responses -punishment. Signals of the transition from one class of actions to another focus the instrumental responses in the first class and inform the contingent responses in the second class. The signals may be innate (USs) or learned (sign-learning); excitatory (leading to more positive actions) or inhibitory (leading to less positive actions). The potency of an action has phylogenetic origins, but may be conditioned by proximity to more potent responses, such as consummation of a reinforcer. With practice instrumental responses may take on increased strength, and in some cases become motivationally autonomous-become habits. Stimuli or responses that signal the availability of more positive actions may become incentive motivators that animals will approach. Discriminative stimuli do not have intrinsic value as reinforcers, but only the value derived from the responses that they release. These forces bend an animal's trajectory through its stimulus-action-time context into a path that leads more directly to positive actions. The association of actions (conditioned responses, operants, and observing responses) with actions of different potency (ultimately unconditioned responses or consummatory behavior) is the primary association in Premackian conditioning. All other types of conditioning may be interpreted as instances of such Premackian conditioning.