When Aristotle introduces virtue in his Nicomachean Ethics, he says that unlike virtues of thought, which can be taught, virtue of character arises from habituation, and that is why a good upbringing is necessary: we need to be instructed in the right habits from an early age. Such a claim implies – and is, I think, usually taken to mean – that there is a sort of seamless transition from being made to brush one’s teeth and share one’s toys to becoming a responsible and morally serious adult: virtue is merely a matter of rationally embracing what one’s parents have already instilled. If one moves from Aristotle’s account to Aquinas’s Christian account, one might be tempted to suppose that the transition from the well-trained child to virtuous Christian involves only a slight modification: of directing existing Aristotelian virtues to a further, supernatural end. The foundational insight of William Mattison’s Growing in Virtue: Aquinas on Habit is that this process is nowhere near so simple as one might suppose.

Mattison argues that any account of how we grow in virtue needs to accommodate Aquinas’s distinction between dispositions and habits. Habits are stable and specified by reason; dispositions lack either stability or rational directedness or both. We are rational animals, and the powers of our soul are suited to be informed and ordered by reason. But those powers can be inclined toward various kinds of actions in ways as well, thanks to our natural constitution or custom. Even before their children are capable of deciding and choosing on their own, parents take great pains to instill customary behaviors – cleanliness, responsibility, emotional regulation and the like. The customary behaviors we instill in our children are not, properly speaking, habits (let alone virtues), yet we all recognize that they are important to instill nonetheless, not least because they provide a ‘visceral formation’ (p.55) that paves the way for virtuous behavior in the future. Those deeply ingrained, customary behaviors that are not virtues are not irrelevant to the authentic habits and virtues we acquire by our repeated acts, and something of the relation between that substrate and acquired virtue anticipates the relation between the virtues acquired by our efforts and the virtues given in grace.

Unlike the dispositions that arise from nature and custom, Mattison argues that virtues in the true sense are both stable and ‘specified by reason’. Reason, he argues, makes a difference not only ‘within’ a virtue but also ‘across’ those virtues and ultimately with respect to life as a whole. It makes a difference within, because it ‘focuses’, so to speak, on our appetitive inclinations. The powers of the human soul are already (albeit ‘indeterminately’ [p.68]) inclined to their various ends: our concupiscible faculty, for instance, is already inclined in a general way to seek what we rationally recognize as pleasant. But, Mattison argues, the virtues incline our appetites to pursue their goods in a more focused way, by creating appetitive inclinations toward more ‘proximate’ ends: to desire to eat and drink the amount conducive to health, or to conform one’s words to reality, etc. Desires focused in this way assist reason’s deliberation. Reason also makes a difference across the virtues, because the virtues that arise through our deliberate and repeated actions necessarily arise together: they are ‘connected’. And, finally, reason makes a difference with respect to life as a whole, by ordering all our actions toward our end.

All the preceding reflection shows why the acquisition of virtue cannot be a mere matter of embracing a natural inclination or even of embracing what one’s parents have already ‘accustomed’ one to do. Those sorts of inclinations are not rational. Virtue, on the other hand, is inherently rational. The rational formation of our appetites does not remove the inclinations that arise from nature or custom, and those inclinations can continue to exert influences of their own, making some virtuous acts easier and others more difficult. Yet as reason comes to specify the powers of our soul more and more stably, the dispositions that arose thanks to nature or custom exercise less and less influence (105).

Just as the specification of reason fundamentally distinguishes dispositions that arise from ‘nature or custom’ from what are properly speaking habits and virtues, so too, Mattison argues, are the virtues given in grace fundamentally distinct from the habits and virtues that arise from our repeated acts. Grace effects change in both our nature and our end. The habits that ordered our powers to the good of reason do not suffice to order us to a nature transformed by grace any more than the inclinations that arose from nature or custom could order us to the good of reason. Just as we become ordered to our natural perfection insofar as our powers come to be specified more and more by reason, so too, Mattison argues, do we become ordered to supernatural beatitude as our powers come to be specified more and more by the order given in grace. And, just as growth in the natural virtues is not a matter of bending existing natural tendencies in a new direction, so too growth in the life of grace is not a matter of merely bending existing acquired virtues in a new direction. Mattison believes that acquired virtues do not remain as virtues after the infusion of grace (and offers a detailed argument to this effect in an appendix), but he does believe that their corresponding inclinations can remain. As in the case of customary behaviors, though, growth in the Christian moral life is not about changing those inclinations but about having the order given by grace pervade our actions more and more.

Mattison’s argument is insightful and important and adds much needed rigor to discussions of Aquinas’s account of virtue, which scholars too often over-simplify. As any important and insightful book should, Mattison’s account raises as many questions as it answers. For instance, while Mattison rightly insists that the early education (or ‘accustomization’) provided by parents is not virtue, he clearly believes it to be important for virtue, not least because of the ‘visceral formation’ it provides. And Mattison seems to envision something similar (albeit also importantly different) between the acquired and infused virtues: the acquired virtues do not simply ‘turn into’ infused virtues, but the formation they provide is nonetheless important. What exactly, though, does that early education or training in acquired virtue provide? Is the right sort of early education mostly good insofar as it prevents certain disorders (like an addiction to sugar or a lack of self-control) that get in the way of virtue later on, or does it actually anticipate acquired virtue in a more robust sense? Is the acquisition of virtue an important preliminary for the life of grace because it prevents the accumulation of vice, or does it anticipate infused virtue more robustly? Either answer would be compatible with the idea that moral training disposes a child for the acquisition of virtue and that the acquisition of virtue disposes one for the gift of the infused virtues. I suspect Mattison is inclined to the ‘more robust’ answer, but I remain uncertain how the details would cash out. One way or the other, this is an important book, one which will be crucial reading for any serious student of Aquinas’s account of virtue.