  However, if one takes there to be more than two attributes, the structure gets quite a bit more complex. One option that has been advanced is that Thought is a special attribute and encompasses ideas of all the modes in all the other attributes (Cf. for example Curley, 1969, 146; and more recently, Melamed, 2009, Chapters 1–2). Thought turns out to be “special” in this kind of interpretation because there are many more modes (ideas) or facets of modes in Thought than there are under any other attribute. Another way of expressing this is by saying that 2P7 is not a biconditional. The requirement of an associated mode goes only in one direction from any mode in any attribute to a mode in Thought. The burden on this type of view is that it must account for the favoring of Thought over the other attributes, and perhaps also for the relation between all the non-Thought modes in the other attributes.