Now prodigality seems always to be directed to some unlawful end, for the sake of which the prodigal squanders his goods. Therefore it seems that prodigality is opposed to temperance and insensibility rather than to covetousness and liberality. I answer that, In morals vices are opposed to one another and to virtue in respect of excess and deficiency. Now covetousness and prodigality differ variously in respect of excess and deficiency. Hence it is evident that prodigality is opposed to covetousness.
Nothing prevents opposites from being in the same subject in different respects.
For a thing is denominated more from what is in it principally. Now just as in liberality, which observes the mean, the principal thing is giving, to which receiving and retaining are subordinate, so, too, covetousness and prodigality regard principally giving. And in like manner it happens sometimes that a man exceeds in giving, and therefore is prodigal, and yet at the same time exceeds in receiving. Wherefore he is prodigal and covetous in different respects. The prodigal does not always exceed in giving for the sake of pleasures which are the matter of temperance, but sometimes through being so disposed as not to care about riches, and sometimes on account of something else.