St. Thomas's Teaching on Moral Virtues

We are human beings that is to say we are parts of a city an earthly city. We cannot as a rule exist as men unless we are working towards cities but we will do so either well or badly and if well then it seems we are either acting by acquired virtue or in the midst of acquiring it. By no means is grace forgotten here. St. Thomas teaches to go back to the first text I quoted that without grace we cannot hope to achieve our natural end. So if an earthly city is doing well with respect to that end it will not have been without healing grace. If we have distinct infused moral virtues as part of the latter effect what does the former effect consist morally?