He [MacIntyre] explains the concept of "goods internal to" a practice by the example of teaching a child to play chess. Initially, he suggests, the child might learn to play only if given, say, money or a piece of candy, which would represent for MacIntyre goods external to the practice of playing this game. In time, however, the child may learn to play for the goods internal to the game -- for example, the achievement of a particular "analytical skill, strategic imagination and competitive intensity." It is only when the child plays the game with these internal goods in mind that she can be truly said to be engaging in a practice. Unlike the money or candy, these internal goods are not particular to the individual; they are for the good of the entire community of practitioners. By having them as a goal the individual practitioner can indeed benefit the others: the child in MacIntyre's example may discover a new chess move that will enhance the game's practice.
As MacIntyre's definition of a practice indicates, there are rules and standards of excellence for a practice that constitute the practice itself. When an initiate enters a particular practice, she must learn the rules and accept the authority of the definitive standards lest she be said not to be engaged in the practice at all. Here MacIntyre stresses the social aspect of the practice: the child cannot obey certain rules and pay attention to a few standards and still be said to play the "complex form of socially established cooperative activity" called chess. Like [*317] the practice's goods, however, its standards and rules are not immutable; they have changed in the history of the practice and are subject to the practitioners' criticism. MacIntyre suggests -- and this seems to be the final point in his definition -- that by pursuing the practice's present goods according to its authoritative standards of excellence and rules, the practitioner might arrive at new conceptions of these goods, standards, and rules.
Drucilla Cornell, Toward a Modern/Postmodern Reconstruction of Ethics, 133 U. PA. L. REV. 291, 316-17 (1985).
I'm not sure I agree with MacIntyre entirely on this (MacIntyre's next step is to say this reunites fact and value by defining virtue through the internal goods of a practice, but Cornell points out several serious problems with this formulation), but it's certainly interesting.