I presume that few who have paid any attention to the history of the Mathematical Analysis, will doubt that it has been developed in a certain order, or that that order has been, to a great extent, necessary — being determined, either by steps of logical deduction, or by the successive introduction of new ideas and conceptions, when the time for their evolution had arrived.
p. v; cited in: Quotations by George Boole, MacTutor History of Mathematics, August 2010. - A treatise on differential equations (1859)