popper-logic-scientific-discovery

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some structural components of a theory of experience
justify the preference for a theory in the light of its corroboration, that is, of
the present state of the critical discussion of the competing theories,
which are critically discussed and compared from the point of view of
assessing their nearness to the truth (verisimilitude). The current state
of this discussion may, in principle, be reported in the form of their
degrees of corroboration. The degree of corroboration is not, however,
a measure of verisimilitude (such a measure would have to be timeless)
but only a report of what we have been able to ascertain up to a certain
moment of time, about the comparative claims of the competing theories
by judging the available reasons which have been proposed for and
against their verisimilitude.
(2) A metaphysical problem raised by the idea of verisimilitude is:
are there genuine regularities in nature? My reply is ‘yes’. One of the
arguments (non-scientific but perhaps ‘transcendental’; see pp. 384–5)
in favour of this reply is: if no regularities were apparent in nature then
neither observations nor language could exist: neither a descriptive nor
an argumentative language.
(3) The force of this reply depends on some kind of commonsense
realism.
(4) The pragmatic problem of induction solves itself: the practical
preference for the theory which in the light of the rational discussion
appears to be nearer to the truth is risky but rational.
(5) The psychological problem (why do we believe that the theory so
chosen will continue to be worthy of our trust?) is, I suggest, trivial: a
belief or trust is always irrational, but it may be important for action.
(6) Not all possible ‘problems of induction’ are solved in this way.
(See also my forthcoming book: Objective Knowledge: An Evolutionary
Approach.)