The Economy of Thought in Mach, Poincaré and Duhem

In this work, we describe the concepts of complexes of sensations, economy of thought and causality, conventionalism in mathematics and natural science, distinction between metaphysics and science, on Ernst Mach, Henri Poincaré and Pierre Duhem. We intend to emphasize the characteristic common to the thought of these three thinkers: the economic function of thought. This ideas of Ernst Mach, Henri Poincaré and Pierre Duhem, give an image of science that does not distinguish between a context of discovery and a context of justification and, therefore, they do not see logic as a necessary and sufficient condition to analyze and justify scientific knowledge.