  According to Hume, intentional actions are the immediate product of passions, in particular the direct passions, including the instincts. He does not appear to allow that any other sort of mental state could, on its own, give rise to an intentional action except by producing a passion, though he does not argue for this.  The motivating passions, in their turn, are produced in the mind by specific causes, as we see early in the Treatise where he first explains the distinction between impressions of sensation and impressions of reflection: