Scanlon argues the concept of well-being is that of a transparent and inclusive good. Well-being is an inclusive good because it
“is made up of other things that are good in their own right, not made good by their contribution to it” (1998: 127),
Well-being is made up, for example, by things that can be abstractly described as forms of enjoyments and accomplishments. Such things are valuable in their own right:
“If you ask me why I listen to music, I may reply that I do so because I enjoy it. [...] [In order to explain why I strive to succeed in philosophy] it would make [...] sense to say that I work hard at philosophy because I believe it is worthwhile, or because I enjoy it, or even because I long for the thrill of success.” (1998: 126-127)
(Notice that what is in question here is the notion of a reason, taken as the sort of thing that can make sense of a choice, an action, or a desire. A reason can make sense of an action by showing it to be called for; for some actions this can be done by showing that the action brings about a desirable consequence. The reason for an action is not a desire, unless the latter is supported by a correct “evaluation of the desired object as good – as, for example, pleasant, interesting, advantageous, stature-enhancing, decent, and the like” as Quinn (1998: 200) writes. The justification of an action or a choice requires facts belonging to the latter category, that is, facts such as that something is pleasant or interesting, not the facts about what a person desires. According to Scanlon, whenever a desire can be said to provide a reason, it does only as a further consequence of these other class of facts See this post.)
According to Scanlon, the concept of well-being is also evaluatively transparent, meaning that “the things that contribute to it are valued primarily for other reasons” (1998: 129). What Scanlon means is that, even if a valuable accomplishment (i.e. climbing the Himalaya) increases our well-being, that fact that it does cannot be the reason for which I took it up to do it.
Summing up. well-being is not only an inclusive good – meaning constituted by things that are good or choiceworthy in their own right – but also transparent, because, for agent p, knowing that some choiceworthy things constitute his or her own well-being does not make them more valuable in p's eyes.
In other words the transparency of well-being derives from the fact that facts.
A. “A life that includes enjoyment is a better life”
B. “My life will be more successful if I am successful in my main aims, insofar they are rational”
do not give the agent any further reason to play tennis or strive to succeed in philosophy;(in addition, that is, to the fact that playing tennis is enjoyable and that a job as a philosopher is prestigious, or that philosophy is intrinsically rewarding).