SummaryThe philosophical core of a psychological theory of cognitive (thought) processes (Aebli 1980/81) is developped and commented, focussing on the problem of intentionality, this term being taken in the normal and in the phenomenological (Brentano/Husserl) sense. Actions, perceived processes, their states and results, operations (sensu Piaget) and concepts are seen as related insofar as they all establish relations between elements, are generated by construction and can be objectivated. These acts and/or the objectives that control them, are intentional insofar as their structure is activated. Such activation is characteristic of living systems. Intentionality sensu Brentano/Husserl is limited to acts of presentation, a contemplative conception which lacks the constructivity and the dynamism of our pragmatistic concept of action and thought.