Quote from A Course in Miracles Text Chapter 4 - THE ILLUSIONS OF THE EGO.

T-4.II.1. It is reasonable to ask how the mind could ever have made the ego. 2 In fact, it is the best question you could ask. 3 There is, however, no point in giving an answer in terms of the past because the past does not matter, and history would not exist if the same errors were not being repeated in the present. 4 Abstract thought applies to knowledge because knowledge is completely impersonal, and examples are irrelevant to its understanding. 5 Perception, however, is always specific, and therefore quite concrete.