Perhaps the biggest difference in the use of purposive action as a general term in preference to intentionality is in the difference between an act and an intention. Intentionality is wholly absorbed in the broad concept of purpose, it is in relation to the field of possibilities but is reserved, reservatus. The action is irreversible and only in this way does directionality actually appear. The action is singular and defines an order that was not necessarily present in the intention. It is something like the so-called collapse of the wave function. The latter, which you could say expresses intention in a general manner, evolves purely deterministically, and the associated probabilities can be precisely calculated, but each individual event is always an ungrounded and indeterminable choice. It is little wonder that this has been seen as having some sort of deep connection to consciousness, although the details of this connection are never spelled out with adequate precision. The notion of consciousness is of course itself unclear, but it perhaps belongs in the same family as intention, or intentionality, or indeed attention. There is a certain detachment implicit in it, it is a "smoker's" way of being present at the event, of reserved participation. Will is closer in spirit to the fatality of choice, and, in so far as it is realised to be a senior concept to that of consciousness or intentionality, it is, if not blind, quite alien to the class of visual metaphors.