Scale-based models of weighing reasons face challenges concerning the context sensitivity of weight, the aggregation of weight, and the methodology for determining what the weights of reasons are. I resolve these challenges.

In this paper I critically examine the implications of the uncodifiability thesis for principlism as a pluralistic and non-absolute generalist ethical theory. In this regard, I begin with a brief overview of W.D. Ross’s ethical theory and his focus on general but defeasible prima facie principles before turning to 2) the revival of principlism in contemporary bioethics through the influential work of Tom Beauchamp and James Childress; 3) the widespread adoption of specification as a response to the indeterminacy of abstract (...) general principles and the limitations of balancing and deductive approaches; 4) the challenges raised to fully specified principlism by the uncodifiability thesis and 5) finally offer a defense of the uncodifiability thesis against various critiques that have been raised. (shrink)