Objection 1. It would seem that domestic should not be reckoned a part of prudence. For, according to the Philosopher (Ethic. vi, 5) "prudence is directed to a good life in general": whereas domestic prudence is directed to a particular end, viz. wealth, according to Ethic. i, 1. Therefore a species of prudence is not domestic.
Objection 2. Further, as stated above (Question 47, Article 13) prudence is only in good people. But domestic prudence may be also in wicked people, since many sinners are provident in governing their household. Therefore domestic prudence should not be reckoned a species of prudence.
Objection 3. Further, just as in a kingdom there is a ruler and subject, so also is there in a household. If therefore domestic like political is a species of prudence, there should be a paternal corresponding to regnative prudence. Now there is no such prudence. Therefore neither should domestic prudence be accounted a species of prudence.
On the contrary, The Philosopher states (Ethic. vi, 8) that there are various kinds of prudence in the government of a multitude, "one of which is domestic, another legislative, and another political."
I answer that, Different aspects of an object, in respect of universality and particularity, or of totality and partiality, diversify arts and virtues; and in respect of such diversity one act of virtue is principal as compared with another. Now it is evident that a household is a mean between the individual and the city or kingdom, since just as the individual is part of the household, so is the household part of the city or kingdom. And therefore, just as prudence commonly so called which governs the individual, is distinct from political prudence, so must domestic prudence be distinct from both.
Reply to Objection 1. Riches are compared to domestic prudence, not as its last end, but as its instrument, as stated in Polit. i, 3. On the other hand, the end of political prudence is "a good life in general" as regards the conduct of the household. On Ethic. i, 1 the Philosopher speaks of riches as the end of political prudence, by way of example and in accordance with the opinion of many.
Reply to Objection 2. Some sinners may be provident in certain matters of detail concerning the disposition of their household, but not in regard to "a good life in general" as regards the conduct of the household, for which above all a virtuous life is required.
Reply to Objection 3. The father has in his household an authority like that of a king, as stated in Ethic. viii, 10, but he has not the full power of a king, wherefore paternal government is not reckoned a distinct species of prudence, like regnative prudence.
Source: Summa Theologica (New Advent)