The next questions all depend crucially on two things that have been established about habitudes:
(1) They specify possible actions out of multiple possible actions.
(2) They belong to something only insofar as it is potential in some way.
Can the intellect have habitudes?
It is clear that there are habitudes associated with the intellect, and this is assumed by St. Thomas's argument, but the question is whether the intellect itself has habitudes. A significant position that St. Thomas wants consistently to argue against is the position that held that we all have one intellect; if you hold this position, it's obvious that intellect-associated habitudes like knowledge vary from person to person, so they would have to be in the sensitive powers. To this Aquinas responds:
But this position, first of all, is against the intention of Aristotle, for it is manifest that sensitive powers are not rational by essence but only by participation, as is said in Ethic. I. And the Philosopher puts intellectual virtues, which are wisdom, knowledge, and understanding, in that which is rational by essence. Thus they are not in sensible powers but in the intellect itself. He also explicitly says, in De Anima III, that the possible intellect when it it made singular, that is, when it is reduced into the act of singulars by intelligible species, then comes to be according to act in the same way that a knower is said to be actual, which indeed happens when someone is able to work through himself, to wit, by considering; and even then it is in some way potential, but not as it was before learning and discovering. Therefore the possible intellect itself is that in which there is a habitude of knowledge by which it can consider even when it does not consider.
And second, this position is against the truth of the thing. For just as the power belongs to that which the working does, so too the habitude belongs to that which the working does. But to understand and to consider is an act proper to the intellect. Therefore the habitude by which one considers is properly in the intellect itself. (ST 2-1.50.4)
A few points are worth noting here.
(1) The first argument, from the mind of Aristotle, especially occurring immediately after the discussion on sensitive powers, indicates that Aquinas does not intend his position on habitudes in the sensitive powers to be a substantive change from Aristotle.
(2) Both arguments here also establish that the intellect is a free power; that is, in and of itself, it is capable of multiple possibilities, since this is a requirement for having a habitude non-derivatively and in the most proper sense.
(3) They both, of course, also imply that the human intellect, contrary to Aquinas's opponents, is not shared but individual.
(4) It follows from this position that habitudes belong to the potential intellect (because it can in some way be potential) and not the agent intellect.
Can the will have habitudes?
I reply that it must be said that every power that can be in diverse ways ordered to acting needs a habitude by which it can be well disposed to its act. But the will, since it is a rational power, can be in diverse ways ordered to acting. And thus it is fitting to put in the will some habitude by which it is well disposed to its act. It is also apparent from the very notion of habitude that it is principally ordered to the will, in that habitude is something one uses when one wills, as said above. (ST 2-1.50.5)
As St. Thomas notes in a reply to an objection (ad 2), this is because the will is more like the potential intellect than the agent intellect, in being both mover and moved. That is to say, the will, while not active, is not a purely active power, but involves a sort of potentiality by its nature.
Can angels have habitudes?
Angels, of course, differ from us in not being physical, so asking whether angels can have habitudes is not mere curiosity about angels, but a way of asking the question of whether having habitudes, even in the intellect and will, depends on the body, or on being physical or material in some way. Do we have habitudes only because we have bodies, so that habitudes are primarily concerned with bodily life? Aquinas holds that what matters for habitudes is not materiality but potentiality, and since angels are not pure act like God, they can have habitudes. From this, of course, it follows that not all habitudes are concerned with corporeal life.
However, with respect to this habitude, angelic intellect has itself differently from human intellect. For human intellect, because it is lowest in the intellectual order, is potential with respect to all intelligibles, just as prime matter with respect to all sensible forms, and therefore it needs some habitude to all understanding. But angelic intellect does not have itself as pure potential in the genus of intelligibles, but as a sort of act, although not as pure act (which is God's alone) but with mixture of some potential, and having less of potentiality the higher it is. (ST 2-1.50.6)
Of the kinds of habitude, the angels do not need habitudes with respect to nature, because they are not material, although it seems that they can have them, but they can have habitudes with respect to operation, and indeed need such habitudes to be united with God (a way of acting well), "by which they are conformed to God." (It follows from this, of course, that it is in principle possible for us also to have such godly habitudes, which will play a significant role in Aquinas's theology of grace.)
The parts that are mutually disposed by angelic habitudes are not physical parts, of course, but intelligible objects and volitional ends.
