Note 328 — Chapter XXII · [319]
Reading edition
"We find that we take for granted irresistibly that each kind [of thing] has some character which distinguishes it from other classes.... What is the foundation of this postulate? What is the ground of this assumption that there must exist a definition which we have never seen, and which perhaps no one has seen in a satisfactory form?... I reply that our conviction that there must needs be characteristic marks by which things can be defined in words is founded upon the assumption of the necessary possibility of reasoning." (W. Whewell: Hist. of Scientific Ideas, bk. viii. chap. i, § 9.)