 Rationalist ethics so conceived faces the following obstacles in the Enlightenment. First, as implied above, it becomes increasingly implausible that the objective, mind-independent order is really as rationalist ethicists claim it to be. Second, even if the objective realm were ordered as the rationalist claims, it remains unclear how this order gives rise (on its own, as it were) to obligations binding on our wills. David Hume famously exposes the fallacy of deriving a prescriptive statement (that one ought to perform some action) from a description of how things stand in relation to each other in nature. Prima facie, there is a gap between the rationalist’s objective order and a set of prescriptions binding on our wills; if a supreme legislator must be re-introduced in order to make the conformity of our actions to that objective order binding on our wills, then the alleged existence of the objective moral order does not do the work the account asks of it in the first place.