Re Michael Gibbons' point about normative influences, from John Davis There surely must be different levels of normative influence. On the one hand, one has reasonably well defined moral theory, such as utilitarianism, rights theory, Rawls, etc. On the other hand, one has concepts which are more loosely value-laden, such as freedom, progress, class, etc. I think it is the latter people are thinking of in the current context, but what may be more interesting is the degree to which these value-laden notions (sometimes better thought as ideological notions) support or bias a purportedly positive analysis of facts and causes as implying a particular moral theory. That is, if we use the language of freedom all the time (say, to the exclusion of unmet needs), to what extent does that mean that our science or positive theory so-called only 'fits' a rights-type moral theory? Or, if we use the language of preference satisfaction (the value-laden instrument), to what extent does it impair speaking about social welfare as including justice considerations? Given that social science discourse is value-laden, then, how does one keep it open to multiple moral theory perspectives, all of which philosophers can defend more or less successfully in principle.