If it were construed as an account of physical practice, it would be misleading. Physicists do not start from hypotheses; they start from data (though not in the inductivist fashion). By the time a law has been fixed into an H-D system, really original and physical thinking is over. The pedestrian process of deducing observation statements from hypothesis comes only after the physicist sees that the hypothesis will at least explain the initial data requiring explanation'3 . Reacting to Popper's contention that the context of discovery is irrelevant from the methodological point of view, Hanson says, ‘Galileo struggled for 34 years before he was able to advance his constant acceleration hypothesis with confidence. Is this conceptually irrelevant? Was it only the predictions from his hypothesis which commend it to Galileo? The philosopher of science must answer “NO”'4 . Discussing in detail the process by which Kepler arrived at his final position, Hanson concludes, ‘Kepler never modified a projected explanation capriciously: he always has a sound reason for every modification he made. When exactly satisfied the observations it stood upon a totally different logical footing from what it would if it has been struck out at random… and has been found to satisfy observations. Kepler shows his keen logical sense in detailing the whole process by which he finally arrived at the true orbit. This is the greatest piece of retroductive reasoning ever performed'5 .
Notes and References
'3N.R. Hanson, Patterns of Discovery , Cambridge University Press
'4Ibid. , p. 172
'5Ibid. , p. 84