 As was shown earlier  (§4.4),  philosophical definitions aiming to avoid all values have been proposed, relying on appeal to allegedly value-neutral statistical norms, and adaptive function, respectively. The vulnerability in Boorse’s (1997) statistical definition, where normal function is determined according to the person’s reference class, identified by such criteria as age, and sex, lies both with assigning the appropriate reference class, a process that inevitably re-introduces values, and at the point on a continuous distribution curve where deviance from the mean is granted the status of dysfunctional, an assessment also involving normative judgments (Bolton 2008). Recognizing that a trait may be dysfunctional in evolutionary terms without being disvalued, and disvalued without being evidence of dysfunction, Wakefield’s two-part definition explicitly accommodates the evaluative element marking the category. This attempt to provide a naturalistic and value free evolution-based account of “function” and “dysfunction” has been subject to a range of damaging objections, including the claim that biological dysfunction is not, as promised, value neutral, carrying as it does a preference for evolutionary fitness. Discerning what would be the maximal response in terms of perpetuating the species represents another of these objections, since no agreed-upon conclusion about this can be drawn in a value-neutral, or perhaps any, way. (See Murphy &amp; Stich 2000.)