Can two objects be the same color? Is it possible for both a t-shirt and a car to be red? If you agree that both objects can share the same redness, then this color red has an existence that is repeatable, it is what philosophers call a “universal.” But in what way can “redness” be said to exist other than in the particular objects that seem to be the same color? Isn’t the red of the t-shirt actually a different red than that of the car? John Hamer of Toronto Centre Place will outline the philosophical problem of universals, how it was understood in Antiquity and the Middle Ages, and why the question remains open today.