We mentioned above that Lagrange had a 'no teaching' clause written into his contract but the Revolution changed things and Lagrange was required to teach. However, he was not a good lecturer as Fourier, who attended his lectures at the École Normale in 1795 wrote:
Namin na nabanggit sa itaas na Lagrange nagkaroon ng 'hindi pagtuturo' sugnay na nakasulat sa kanyang kontrata Revolution ay nagbago ngunit ang mga bagay-bagay at Lagrange ay kinakailangan upang turuan. Gayunman, siya ay hindi isang magandang lektor bilang mga Fourier, na pumasok sa kanyang lektura sa École Normale sa 1795 wrote: