 In a similar vein, since many mixed modes, which include all moral concepts, are arbitrary mental constructs, it follows that we create moral concepts by producing their definitions. Since the real and nominal essences of mixed modes are the same, it follows that if we know the real essence of lying (knowingly and falsely asserting that ‘p’ with the intention to mislead someone whom we ought not to mislead, etc.), we can deduce from that idea all the components of lying, and so there is nothing more to know about lying than the ideas contained within its definition. A problem with Locke’s account here is that, as John Mackie points out, social scientists seek out the real essences of social phenomena such as adultery, incest, jealousy, lying and suicide, but understanding these complex phenomena involves more than simply understanding the meaning of the word. If we are to understand why people lie, we must know more than a definition of lying. Of course, it is possible for Locke to argue that once we understand all that is included in lying, we have uncovered its real essence, why people lie, and the many ways they do so, however, are separate questions that we cannot expect to be decided by a semantic theory. It is unclear how he would solve the normative problem (see Mackie 1976, pp. 90–91; see also Jolley 1999, pp. 155–161).