From his first publications, Bergson's philosophy attracted strong criticism from different quarters, although he also became very popular and durably influenced French philosophy. The mathematician Édouard Le Roy became Bergson's main disciple. Nonetheless, Suzanne Guerlac has argued that his institutional position at the Collège de France, delivering lectures to a general audience, may have retarded the systematic reception of his thought: "Bergson achieved enormous popular success in this context, often due to the emotional appeal of his ideas. But he did not have the equivalent of graduate students who might have become rigorous interpreters of his thought. Thus Bergson's philosophy—in principle open and nonsystematic—was easily borrowed piecemeal and altered by enthusiastic admirers".