If everything in chemistry is explained in a satisfactory manner without the help of phlogiston, it is by that reason alone infinitely probable that the principle does not exist; that it is a hypothetical body, a gratuitous supposition; indeed, it is in the principles of good logic, not to multiply bodies without necessity.

'Réflexions sur le phlogistique', Mémoires de l'Académie des Sciences, 1783, 505–38. Reprinted in Oeuvres de Lavoisier (1864), Vol. 2, 623, trans. M. P. Crosland