Adding a few words to the Guide to the LSD on Corroboration. The idea is to introduce the “check on the problem” to ask people to consider what they are trying to achieve with confirmation theory. The check on the problem is a good way to focus a discussion that has drifted off into definitions, or just drifted off as so many committees and meetings tend to do.
Popper rejected the possibility of verification of theories, and also the fallback position of numerical probability of theories. So he had to answer the question – what is achieved when a hypothesis passes empirical tests? His answer is the theory of corroboration.
He adopted this term (suggested by the New Zealand soil chemist Hugh Parton) to distance himself from Carnap who wanted to talk about the “degree of confirmation”.
Most of this chapter is occupied with arguments against the idea of attaching numerical probability values to theories by means of inductive logic. One of the defences mounted by the inductivists is to appeal to the uniformity of nature as an “inductive principle” which we cannot live without. For Popper, the uniformity of nature has nothing to do with the logic of induction (attempting to put p values on theories) but,
“It expresses the metaphysical faith in the existence of regularities in our world (a faith which I share, and without which practical action is hardly conceivable). Yet the question before us – the question which makes the non-verifiability of theories significant in the present context – is on an altogether different plane. (252-3)”
The plane that concerned Popper is the logic of testing and the way that the outcome of tests is inevitably uncertain due to the theory-dependence of observations, the Duhem problem and the like. And so the outcome for Popper is that corroboration is about reporting how well a hypothesis has “proved its mettle” by standing up to tests and solving whatever theoretical problem it was designed to address. It may help at this point to consider what Bartley called “the check on the problem”, that is to be clear about the problem that a theory of corroboration (or confirmation) is supposed to solve. Originally it was probably supposed to answer the question, “Is this theory true?” and later “Is this theory probable?”. For Popper, operating with the theory of conjectural knowledge and also considering what he called “the essential incompleteness of all science” (in an Addendum to the second volume of the <i>Postsript to The Logic of Scientific Discovery</i>), the purpose of testing depends on the situation: there may need to be a choice for a practical or technological application, or there may need to be a decision about the next steps of a research program.
“We choose the theory which best holds its own in competition with other theories; the one which, by natural selection, proves itself the fittest to survive. This will be the one which no only has hitherto stood up to the severest tests, but the one that is testable in the most rigorous way. (108)”
