It is obvious, therefore, that in order to be effective a doctrine must not be understood, but has rather to be believed in. We can be absolutely certain only about things we do not understand. A doctrine that is understood is shorn of its strength. Once we understand a thing, it is as if it had originated in us. And, clearly, those who are asked to renounce the self and sacrifice it cannot see eternal certitude in anything which originates in that self. The fact that they understand a thing fully impairs its validity and certitude in their eyes.
