 The work of Cauchy (as well as that of Bolzano) represents a crucial stage in the renunciation by mathematicians—adumbrated in the work of d’Alembert—of (fixed) infinitesimals and the intuitive ideas of continuity and motion. Certain mathematicians of the day, such as Poisson and Cournot, who regarded the limit concept as no more than a circuitous substitute for the use of infinitesimally small magnitudes—which in any case (they claimed) had a real existence—felt that Cauchy’s reforms had been carried too far. But traces of the traditional ideas did in fact remain in Cauchy’s formulations, as evidenced by his use of such expressions as “variable quantities”, “infinitesimal quantities”, “approach indefinitely”, “as little as one wishes” (Kline 1972: 951) and the  like.[27]