3 definitions
Definition.com
The Number (n.) derives its essence from psychology to the same extent as the North Sea derives its existence.
Definition.com
Objectivity (n.) in general is what Frege called a bloodless specter: the relation to the object that no psychology can found.
Definition.com
Unity (n.) cannot be engendered from a multiplicity of positive acts, facts or psychic events; neither unity nor zero can be.