From his Commentary on Aristotle’s Nicomachean Ethics:
It is also shown here that the magistrate’s main duty (for when Aristotle mentions the political faculty, he is speaking of him) is to produce good citizens. It is doubtless important for him to enrich his subjects, to extend the limits of empire, and to fortify the city with defenses and ramparts; but the magistrate’s main job is to produce good citizens. Those who hold the reins of government should think nothing that contributes to this irrelevant to their duty. They will not, as some do, regard the pure and chaste observation of religion as beyond their purview. This being so, the best view is that a very close connection between the magistrate and the ministers of the church is beneficial for states. (Peter Martyr Library Edition, p. 227)
We should now add to this that it ought to be a magistrate’s concern that his people behave virtuously and that their prime virtue be piety. So it will be a good magistrate’s responsibility to do everything possible to see that pure and sincere religion prevails in his territory. Those who do not do this do not keep the true way of governing a state. It is easy to understand how the application of virtue follows from a design to make the citizens good, since the virtues are the causes of goodness. . . .
We see here very clearly which virtues are excluded from this consideration, namely, those of the body. These are commonly said to be four in number—health, shape, clarity of the senses, and strength. . . . Only those located in the soul are to be treated. . . .
Since the soul is the subject of the virtues, he must find out some things about it before discussing its accidents. Aristotle confirms this procedure with a comparison: a doctor acts in exactly the same way, for he studies the nature of the body and the ey before turning his hand to cure them. . . . For medical science is considered far inferior to political science; if therefore the doctor is not ignorant of the limbs he is about to treat and heal, it will be much more important for the politician to learn about the soul in which the virtues are located. This comparison between doctor and politician is quite apposite and appropriate. For just as the former heals the body, the latter seeks to care for the soul with good customs. It is almost as if we were saying that the two principal parts of man are to be governed and restored by a twofold faculty: the soul is entrusted to the statesman and the body to the doctor. Before everything, the doctor wants to know what is proper to each part of the body in its own particular nature, then he observes what thing contrary to its nature is brought on by disease; once he has understood this, he looks for remedies that will bring those parts of the body back to the proper state of their nature. (pp. 266-67)
It is striking in particular how in this latter passage, by appearing to say that the politician’s task is chiefly concerned with the good of the soul, rather than with the body, Vermigli almost perfectly inverts the consensus of modern liberal politics (in both its right-wing and left-wing forms).