Full Idea
Frege has defended the austere view that, in mathematics at least, only stipulative definitions should be countenanced.
Gist of Idea
Frege suggested that mathematics should only accept stipulative definitions
Source
report of Gottlob Frege (Logic in Mathematics [1914]) by Anil Gupta - Definitions 1.3
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.4
A Reaction
This sounds intriguingly at odds with Frege's well-known platonism about numbers (as sets of equinumerous sets). It makes sense for other mathematical concepts.