Full Idea
How can it make sense to ascribe the property 'one' to any object whatever, when every object, according as to how we look at it, can be either one or not one?
Gist of Idea
The number 'one' can't be a property, if any object can be viewed as one or not one
Source
Gottlob Frege (Grundlagen der Arithmetik (Foundations) [1884], §30)
Book Reference
Frege,Gottlob: 'The Foundations of Arithmetic (Austin)', ed/tr. Austin,J.L. [Blackwell 1980], p.41
A Reaction
This remark seems to point to numbers being highly subjective, but the interest of Frege is that he then makes out a case for numbers being totally objective, despite being entirely non-physical in nature. How do they do that?