Zimmerman, he challenged traditional metaphysical ideas with a more "pragmatic" approach saying that only through "calm, informed reflection" on the ways in which people "interact with the environment" and deal with the ensuing consequences can value be ascertained. Virtue ethics and fitting-attitude theory Mason in her article on Value Pluralism introduces virtue ethics as a third way of thinking about the subject of value and describes it as being based on how a person should "be" rather than what a person should "do". Frankena had similarly introduced an "ethics of virtue" as a third approach (following deontology and consequentialism), suggesting that there were two kinds of things that we can value: either the things around us like knowledge or physical objects; or the things inside us like our disposition, attitudes and emotions. Among the latter were the virtues and these he defined as dispositions to act in certain ways. Regarding the virtues, we can either value them in their own right or we can ask whether they tell us something about the nature of value itself. Hursthouse and Pettigrew deal with the first of these options in their article on Virtue ethics, asking questions like "how many virtues are there" and "how do they relate to each other". C.B.Miller, on the other hand, in his article on moral character points to recent work which suggests that the categories used to structure the virtues are the same as those that can be used to structure values. The six "core virtues" listed by Peterson and Seligman have been found to be useful, for example, in the structuring of values in their "Values in Action" or VAI. One of the similarities between virtue theory and fitting-attitude theory is that they both approach the subject of value through an emphasis on the agent. They are "agent-centred" rather than "act-centred" theories, but whereas virtues are defined purely as a disposition to act, fitting-attitude theory embraces the act as well within its field of consideration. Roderick Chisholm in his book, Brentano and Intrinsic Value [1986] suggested that value lies, for example, not just in virtue but in "individuals acting virtuously" or not just in pleasure but in "individuals experiencing pleasure". However, just as there is conceived to be a necessary interaction between the agent and the environment so there is, in other circumstances, a necessary engagement between the agent and an object. Jacobson in his article