"I agree that the idea of time only exists in our imagination. But we have reason to ask whether or not the idea of time and time itself are different from one another. And it seems to me that the metaphysicians, in doing away with the reality of time, have confused time with the notion of it."
LEONHARD EULER. REFLECTIONS ON SPACE AND TIME (Translated from the French by Michael P. Saclolo) http://eulerarchive.maa.org/docs/translations/E149tr.pdf