Thomas Kuhn, The Structure of Scientific Revolutions
p.g. 192 (Postscript)
"When I speak of knowledge embedded in shared exemplars, I am not referring to a mode of knowing that is less systematic or less analyzable than knowledge embedded in rules, laws, or criteria of identification. Instead I have in mind a manner of knowing which is misconstrued if reconstructed in terms of rules that are first abstracted from exemplars and thereafter function in their stead."
"What need we know, Wittgenstein asked, in order that we apply terms
like 'chair', or 'leaf', or 'game' unequivocally and without provoking
That question is very old and has generally been answered by saying
that we must know, consciously or intuitively, what a chair, or a leaf,
or game _is_. We must, that is, grasp some set of attributes that all
games and only games have in common. Wittgenstein, however, concluded
that, given the way we use language and the sort of world to which we
apply it, there need be no such set of characteristics. Though a
"Consider for example the proceedings that we call `games'. I mean board games, card games, ball games, Olympic games, and so on. What is common to them all? Don't say, "There must be something common, or they would not be called `games' " - but look and see whether there is anything common to all. For if you look at them you will not see something common to all, but similarities, relationships, and a whole series of them at that. To repeat: don't think, but look! Look for example at board games, with their multifarious relationships.