  “One calls the equator an imaginary line, but it would be wrong to call it a line that has merely been thought up. It was not created by thought as the result of a psychological process, but is only apprehended or grasped by thought. If its being apprehended were a matter of its coming into being, then we could not say anything positive about the equator for any time prior to this supposed coming into being.” [Gottlob Frege, The Foundations of Arithmetic § 26 (1884: 35)]