Full Idea
Frege regarded the existence of horses as a property of the concept 'horse'.
Gist of Idea
Frege takes the existence of horses to be part of their concept
Source
report of Gottlob Frege (Function and Concept [1891]) by Fred Sommers - Intellectual Autobiography 'Realism'
Book Reference
'The Old New Logic', ed/tr. Oderberg,David S. [MIT 2005], p.17
Related Idea
Idea 18752 'The concept "horse"' denotes a concept, yet seems also to denote an object [Frege, by McGee]