Imago Dei in Those Without Use of Reason

Rebecca at "Rebecca Writes" has often had some excellent discussions about the imago Dei, always underlining that it cannot be simply identified with the use of reason (e.g., here). I was thinking about this in relation to Aquinas earlier today, particularly as found in his De Veritate. There Aquinas says that the presence of God in the mind is the memory of God in the mind. 'Memory' or memoria is a term borrowed from Augustine; for Aquinas it means not actually remembering but a sort of habitual knowledge -- i.e., memoria is a disposition for actual knowing. The presence of God as the memoria of God, however, is prior to any sensation; and since the actualization of our intellects presupposes sensation to think about, the memory of God is prior to any rational activity at all. Indeed, this 'memory' or memorial of God is prior to rational activity as a precondition for thinking at all. It is for this reason that even those who do not actually have the use of reason bear the image of God. It is, of course, the case that the image of God is expressed through things like understanding, love, creative ability, and more. But we do need to distinguish the image of God in itself and the image of God as expressed; the latter is an actualization or activation of the former, and the former is the potential for the latter.