The dual scale model of weighing reasons

The metaphor of weighing reasons brings to mind a single (double-pan balance) scale. for ? go in one pan and the ?? other. relative weights, as indicated by heights two pans scale, determine deontic status ?. This model is simple intuitive, but it cannot capture what weigh correctly. A reason pushes down toward permissibility (has justifying weight) only insofar up impermissibility requiring weight). Thus, Single Scale committed Proportion (first pass): all have same proportion weight. Many normative theories reject Proportion, they are not thereby confused about how reasons. One can be mistaken weight without being weighed. problematic, because appeals image We need scales