(1) While I would wholeheartedly agree with the statement that "setting the definition of flourishing cannot be a task for the empirical sciences", I think this also potentially misses the important role of the empirical sciences not only in understanding the means to flourishing, but also the actual content of the definition itself. With regard to the means, questions such as, "How can we effectively promote forgiveness in practice?" or "What shapes and promotes the experience of love in childhood?" seem of tremendous relevance to the Christian faith, and are amenable to, and have been subject to, considerable insightful empirical investigation (VanderWeele, 2018; Chen and VanderWeele, 2019).
However, I think a more profound and far more difficult question is how the empirical sciences can and should contribute to our understanding of what constitutes flourishing. I agree that the empirical sciences are not to set the definition, but I do think they have a role in understanding the content of that definition. One might, for example, include physical health within a conception of flourishing (the "circumstantial" dimension), but the question of what constitutes bodily health is a matter not only of conceptual specification but of understanding anatomy and physiology. Similarly, good social relationships are also a part of human flourishing, but it is difficult to describe what constitutes such good social relationships without having an (empirical) understanding of how human life is actually lived in its embodied and culturally specific forms.
From a Christian standpoint one would point to loving relationships and all that that entails (1 Corinthians 13:4-7) but what this means within a marriage, or while parenting, or within friendship, cannot be fully understood or appreciated without an experiential and empirical knowledge of how these types of relationships play out and what is required of each. The empirical sciences thus do seem to have some role, perhaps not in the definition of flourishing, but in our understanding of the actual content of that definition, i.e. the definition as it pertains to actual human life. The empirical sciences might not at present be particularly well constituted to provide this important service to theology, but it seems that some of the work of trying to redeem our academic structures and disciplines is to try to shape them so that they are better able to fulfill that role.
(2) There is of course an important role for theology in trying to as fully and adequately as possible specify and describe how human flourishing ought to be understood within the Church. However, it would seem that another important task is to try to find consensus with those from other religious, philosophical and cultural traditions that is as broad as possible (in extent) and as expansive as possible (in content) and that is consistent with and arises out of a Christian vision so as to resist reductionist impulses to restrict notions of well-being to only economic and health-related states, as is the case in most discussion of this topic, at least in the contemporary west. Such more expansive but consensus-based understanding and resistance of reductionist approaches is part of the vision within Maritain's Integral Humanism. It is some of what has motivated our work and approach to flourishing assessment, study, and promotion at the Human Flourishing Program at Harvard (VanderWeele, 2017).
(3) I was somewhat surprised at the characterization that the "circumstantial" dimension (life going well) was considered "passive" and that the "emotional" dimension (life feeling right) was considered "both passive and active". I would have thought that the emotional dimension was in fact the most passive (the "passions" being a response to the perception of circumstances and actions), and that the "circumstantial" was both active and passive. It seems odd to place relationships, or health (or, presumably, knowledge also fits in the circumstantial dimension) as being entirely passive. This may merit some reconsideration, though one could I think also argue that all three of the proposed dimensions have active and passive components, including "righteousness", as per the Scripture reference concerning Romans 14:17 in the brief.
VanderWeele, T.J. (2017). On the promotion of human flourishing. Proceedings of the National Academy of Sciences of the United States of America, 31:8148-8156.
VanderWeele, T.J. (2018). Is forgiveness a public health issue? American Journal of Public Health, 108:189-190.
Chen, Y. Kubzansky, L., and VanderWeele, T.J. (2019). Parental warmth and flourishing in mid-life. Social Science and Medicine, 220:65-72.