Full Idea
Russell defined the rationals as ratios of integers, and was therefore forced to treat the real number 5/8 as an object distinct from the rational 5/8.
Gist of Idea
Russell's approach had to treat real 5/8 as different from rational 5/8
Source
report of Bertrand Russell (The Principles of Mathematics [1903]) by Michael Dummett - Frege philosophy of mathematics 21 'Frege's'
Book Reference
Dummett,Michael: 'Frege: philosophy of mathematics' [Duckworth 1991], p.271