  Yet another reply to the objection is to argue that belief in moral properties (or, more broadly, normative properties) construed in terms of non-naturalism, is indispensable to our deliberation.  The idea behind this strategy is to argue that there is no reason we should privilege explanatory indispensability over deliberative indispensability (see Enoch 2011). One worry about this strategy is that it is not clear that it helps support belief in specifically moral properties, but once we embrace non-naturalist realism about other normative properties there may be no further ontological costs to accepting the appearances about moral properties too.  Like all transcendental arguments, this defense of non-naturalism is subject to worries about why the indispensability of some belief to our deliberation speaks in favor of its truth.  Finally, it is not entirely clear why one must believe in normative properties as construed by non-naturalism in order to deliberate.  A lot of the work of this argument consists in debunking naturalist and expressivist conceptions of moral belief as inadequate for our deliberative purposes.  See both Enoch 2011 and Fitzpatrick 2011 for relevant discussion of this last point.  