Dhamma as indispensible

The following from Bhikkhu Bodhi appears to present an argument against Aristotelianism or reducing or getting rid of cosmology/metaphysics:

The importance of this directly visible side of Dhamma practice cannot be underestimated, as it serves to confirm our confidence in the liberating efficacy of the Buddhist path. However, to downplay the doctrine of rebirth and explain the entire import of the Dhamma as the amelioration of mental suffering through enhanced self-awareness is to deprive the Dhamma of those wider perspectives from which it derives its full breadth and profundity. By doing so one seriously risks reducing it in the end to little more than a sophisticated ancient system of humanistic psychotherapy. - http://www.vipassana.org/resources/bodhi/dhamma_without_rebirth.php (emphasis mine)

Buddhist Publication Society Newsletter cover essay #6 (Spring 1987)
Copyright © 1987 Buddhist Publication Society

If we incorporate this into our understanding of Buddhist ethics, it means we must object (at least in par) to Damien Keown's (1992/2001) focus on the goal of nirvana "in this lifetime." Of course he does this to maintain a focus on a robust moral agent and avoid issues of rebirth and the moral nature of an awakened one. He does address both of these but seeks to keep the focus on moral conduct, sīla.

But arguments such as Bhikkhu Bodhi's above, and others, suggest that we broaden the discussion to understand Dhamma in its "full breadth and profundity." In doing so, we must examine Dhamma in all its metaphysical/cosmological complexity.