There are five levels in the motivational system: Plans, Responses, Impulses/inhibitions, Motives (wants and needs) and Evaluations (beliefs about what is good or bad etc.).

Each level is influenced directly by factors outside of the motivational system including stimuli, ideas and emotions. The flow of influence through the system is that responses are influenced by impulses/inhibitions which are influenced by motives which are influenced by evaluations which are influenced by plans.

This means that plans can only influence responses if they generate evaluations at the appropriate time; beliefs about what is good or bad etc. can only influence responses if they generate wants or needs; wants or needs can only influence responses if they generate impulses or inhibitions.