  In Quine’s view, philosophers can, therefore, do no better than to adopt the standpoint of the best available knowledge, i.e. science, in some suitably broad sense. We adopt what he calls “the fundamental conceptual scheme of science and common sense” (1960, 276). Philosophers are thus to be constrained by scientific standards. In (1974) he puts it this way: “In our account of how science might be acquired we do not try to justify science by some prior and firmer philosophy, but neither are we to maintain less than scientific standards. Evidence must regularly be sought in external objects, out where observers can jointly observe it….” (1974, 34f.)