"To substitute is to accept instead. If you would but consider exactly what this entails, you would perceive at once how much at variance this is with the goal the Holy Spirit has given you, and would accomplish for you. To substitute is to choose between, renouncing one aspect of the Sonship in favor of the other. For this special purpose, one is judged more valuable and the other is replaced by him. The relationship in which the substitution occurred is thus fragmented, and its purpose split accordingly. To fragment is to exclude, and substitution is the strongest defense the ego has for separation."