Niaz (1990) presents arguments in favor of the retention of Piaget’s epistemic subject as a theoretical construct to guide research and practice in science education and psychology. The intent of this article is to point out the weaknesses of those arguments and to suggest that the weight of evidence argues against the existence of the logical thinker postulated by Piaget. Therefore, contrary to Niaz’s conclusion that the acceptance of Piaget’s epistemic subject will facilitate the development of cognitive theories with greater explanatory power, the conclusion is reached that Piaget’s epistemic subject is dead and that continued acceptance of this aspect of Piagetian theory would be counterproductive.

This study tested the constructivist hypothesis that the acquisition of domain‐specific conceptual knowledge (declarative knowledge) requires use of general procedural knowledge. More specifically, it was hypothesized that use of a general pattern of hypothetico‐deductive reasoning is necessary for the acquisition of novel domain‐specific concepts. To test this hypothesis 314 high school biology and chemistry students were first tested to determine whether or not they were skilled in the use of hypothetico‐deductive reasoning. Based on this test, students were classified as reflective, transitional, or intuitive thinkers. All students were then presented with a series of four concept‐acquisition tasks. It was predicted that reflective (hypothetico‐deductive) thinkers would acquire the concepts while intuitive (empirico‐inductive) thinkers would not. Transitional thinkers were expected to be partially successful. These predictions were confirmed as skill in hypothetico‐deductive reasoning (developmental level), but not age, was highly correlated with performance on the concept acquisition tasks (χ^2 = 71. 14, p < 0. 00001). This result was interpreted to be supportive of the constructivist hypothesis.