There is, it appears, the appearance of truth, 'verisimilitude,' and, over and against that, the reality of truth, truth itself. Or so it appears, but perhaps it is not true, or not any longer. Certainly, the certification of true truth and genuine knowledge in their classic senses—as, for example, the accurate affirmation or faithful representation of an altogether autonomous reality—has proved elusive. And, as we know, alternative conceptions of truth and knowledge—as, for example, the relatively coherent, relatively viable, and relatively stable products of various social and institutional practices—have been proposed in recent years ... and have proved relatively coherent, viable, and stable. These alternative conceptions have emerged from a number of fields: philosophy, of course, especially along lines marked by Nietzsche and Wittgenstein, but also other fields, such as biology and psychology, which have yielded important redescriptions of the interactive mechanisms of language, perception, and cognition, and, of particular interest here, the history and sociology of science, which, during the past two decades, have developed a pragmatist/rhetoricist approach to these questions often referred to as 'constructivism.'