The spectrum of commonly stated aims of science may be identified by its extremes: understanding and utility. Understanding involves description (and thus classification), explanation, and encapsulation of possibilities: answers to "What?" "Why?" and "What is possible?" and often also to "How?" (SVF, ch. 5). Scientific understanding is expressed in theories and it is empirically grounded. The criteria used for appraising scientific understanding will be called, following Kuhn and others, cognitive values (SVF, ch. 3). They include (e.g.) empirical adequacy, explanatory power and inter-theoretic consistency, features whose manifestation in theories is for the most part a matter of degree. Cognitive values are the features whose high manifestation is desired of acceptable theories, theories which express sound understanding. Modern science has been an unstoppable font of sound understanding, which in turn has been widely, effectively and usefully applied. Part of the explanation usually offered for this two-fold success draws upon the view that science is value free, a view that is best treated (SVF, chs 1, 4, 10) as the conjunction of three distinct ideas: impartiality, neutrality, and autonomy.