„Calculations are to the economic science what bones are to the human body. Without them it will always be a vague and confused science, at the mercy of error and prejudice.“
— François Quesnay
François Quesnay in letter to Mirabeau (Archives Nationales, Ms. 779, 4 bis, p.2 note); as cited in: Richard Van Den Berg and Albert Steenge. "Tableaux and Systèmes. Early French Contributions to Linear Production Models." Cahiers d'économie Politique/Papers in Political Economy 2 (2016): 11-30.