Therefore, I have attacted [the problem of the catenary] which I had hitherto not attempted, and with my key [the differential calculus] happily opened its secret. Acta eruditorum — Gottfried Leibniz Copy Share Image
![“Therefore, I have attacted [the problem of the catenary] which I had hitherto not attempted, and with my key [the differential calculus] happily opened its secret. Acta eruditorum” quote by Gottfried Leibniz](https://sms4smile.com/quotes/img-quotes/11d/gottfried-leibniz-3585_calculus_therefore-i-have-attacted-the-problem-of_2735449.jpg)