Abstract
Social determinists have argued that the occurrence of independent discoveries and inventions demonstrates the inevitability of techno-scientific progress. Yet the frequency of such multiples may be adequately predicted by a probabilistic model, especially the Poisson model suggested by Price. A detailed inquiry reveals that the Poisson distribution can predict almost all the observed variation in the frequency distribution of multiples collected by Merton, and by Ogburn and Thomas. This study further indicates that: (a) the number of observed multiples may be greatly underestimated, particularly those involving few independent contributors, (b) discoveries and inventions are not sufficiently probable to avoid a large proportion of total failures, and hence techno-scientific advance is to a large measure indeterminate; (c) chance or 'luck' seems to play such a major part that the 'great genius' theory is no more tenable than the social deterministic theory.