ABSTRACT
Both the use of logical models to describe the development of thinking and the characterization of concepts as hypotheses form part of a general assumption that scientific and everyday thinking have certain features in common. Inductivists assert that the scientist accumulates knowledge by careful observation of data; by inductive reasoning he passes from statements of particular facts to general statements which comprehend them. Deductivism maintains that particular truths are attained by relating hypotheses deduced from theories to the empirical evidence. Psychologists concerned with deductive reasoning have assessed the capacity of their subjects on problems connected with the rules of syllogistic reasoning and of propositional logic. However, most studies of deductive reasoning have concentrated on personal and environmental factors which limit the subject's ability to think logically. The difficulty of discerning a clear distinction between inductive and deductive reasoning in the way in which people actually think is also demonstrated by the work of P. C. Wason and his colleagues.
