Full Idea
It is impossible that the ordinals should be, as Dedekind suggests, nothing but the terms of such relations as constitute a progression. If they are anything at all, they must be intrinsically something.
Gist of Idea
Ordinals can't be defined just by progression; they have intrinsic qualities
Source
Bertrand Russell (The Principles of Mathematics [1903], §242)
Book Reference
Russell,Bertrand: 'Principles of Mathematics' [Routledge 1992], p.249
A Reaction
This is the obvious platonist response to the incipient doctrine of structuralism. We have a chicken-and-egg problem. Bricks need intrinsic properties to make a structure. A structure isomorphic to numbers is not thereby the numbers.