To have learned how to stand back in some measure from our present desires, so as to be able to evaluate them, is a necessary condition for engaging in sound reasoning about our reasons for action. Here one danger is that those who have failed to become sufficiently detached from their own immediate desires, for whom desire for their and the good has not become to a sufficient degree overriding, are unlikely to recognize this fact about themselves. And so what they present to themselves as a desire for their own good or for the good may in fact be and often enough is some unacknowledged form of infantile dsire, a type of desire that has been protected from evaluative criticism. Hence in deliberating they both reasno from unsound premises and act from badly flawed motivation. Sound practical reasoning and good motivation are related in sometimes complex ways, but an incapacity to distance oneself from one's desires is a danger to both.
[Alasdair MacIntyre, "Vulnerability, flourishing, goods, and 'good'", Dependent Rational Animals, Open Court (Chicago: 1999), p. 73.]
