Vii. Comparative Inductive Logic § 87. Hempel's Analysis of the Concept of Confirming Evidence

Some interesting investigations by Hempel concerning the concept of ~on­ firming evidence are here discussed. Hempel shows correctly that two wIdespread conceptions are too narrow: Nicod's criterion (the law fall swans are white' is confirmed by observations of white swans and only by these) and th.e prediction-criterion (a hypothesis is confirmed by given evidenc~ if and only If one part of this evidence can be deduced from the ot~e.r part ':"lth .the .help of the hypothesis), Hempel lays down some general cond,ltlons whIch, III his VIew, a concept must fulfil in order to be an adequate exphcatu~ of the concept .of confirming evidence. It is shown that some of these condItIOns are not valId, that is to say, no adequate explicatum can fulfil them.