There are many places in which Griffin talks as if statements about what is valuable to a person and the concept of well-being could be used interchangeably:
“If a father wants his children to be happy, what he wants, what is valuable to him, is a state of the world, not a state of his mind; merely to delude him into thinking that his children flourish, therefore, does not give him what he values” (13)6
“that is what gives the [present account of well-being] its breadth and attraction as a theory of what makes life valuable” (14)
“If the Experience Requirement excludes these values [accomplishments, close authentic personal relationships] from 'utility', then 'utility will have less and less to do with what these persons see as making their own lives good.” (19) “If either I could accomplish something with my life but not know it, or believe that I had but not really have, I should prefer the first. That would be, for me, for me, the more valuable life.
Finally, after the previous passage, he recognizes that there is a problem. The notion of valuable life can mean many things:
'Valuable life', of course, is full of ambiguity. It can mean a life that is valuable because of its value ot other persons. It can mean a morally valuable life, or an aesthetically valuable one, or one valuable in terms of some code, such as a code of chivalry. But my ground for preferring the first sort of life would not be any of these; I should prefer it because it would be, considered on its own, considered simply as a life I must lead [This introduces the criterion of “a life considered on its own” . I will show that it is impossible to distinguish the ground of preferring this life from a perfectionist one if not by committing oneself to a definition of what “a life considered on its own is” that entails a mental state account of well-being], a more fulfilling one. [“fulfilling” has both a perfectionist and a welfarist connotation. Griffin can be read as committing himself to the view that a valuable life, in the sense in question, is a a life that rates high in terms of perfection, when it is evaluated “on its own”. But this would be contentious for a definition: we can imagine counterexamples in which a life is made better in terms of perfection by realizing some feature, but not better prudentially." ] So it is a value that has to be found a place within the bounds of 'utility'.
So here we have a further specification of what we mean when we use the concept of well-being or prudential value. What is in question is not what makes a life valuable, or good, simpliciter, but what makes it good or valuable on its own. I expected Griffin to the intuitive idea of what is "good for the person who lives it", as Sumner and Crisp do. Griffin does this here (see 8).