 While the aforementioned controversies have not been settled, the following assumptions will be made in the remainder of this entry: i) the objects of preference may be heterogeneous prospects, incorporating a rich and varied domain of properties, ii) preference between options is a judgment of comparative desirability or choice-worthiness, and iii) preferences satisfy both Completeness and Transitivity (although the former condition will be revisited in  Section 5).  The question that now arises is whether there are further general constraints on rational preference over options.