To be able to restrict one's practical reasoning to what will enable one to discharge the responsibilities of one's socially approved roles is to have imposed on one's thinking a set of artificial restrictions. It is to have arbitrarily closed one's mind to certain possibilities of action. And, although others may provide one with motives for effecting such a closure, it is only with one's own active co-operation that the habits of mind can be developed which make such closure possible.
Alasdair MacIntyre, "Social Structures and their Threats to Moral Agency," Philosophy, vol 74 no 289 (July 1999) p. 326.
