Chapter XVI. Discernment of Absolute Truth - p.176

It is impossible to define absolute truth, as that which is absolute is beyond definition, containing within itself the elements of all definitions that might be formulated with regard to the truth. But for practical purposes we can say that absolute truth is the real or the whole truth in its changeless condition without any colorings or modifications whatever from the mind of man. Therefore to discern absolute truth the human mind must transcend all relative and isolated viewpoints of truth, and look upon the whole truth as it is in its fundamental and unmodified state.

This, however, is not possible so long as the ordinary senses are depended upon exclusively, because the senses invariably take special or isolated viewpoints, not being able to see anything from all points of view. For this reason the senses do not see things as they are in themselves all around, so to speak, but see things only as they appear from certain viewpoints. What is discerned from these viewpoints, however, is true as far as it goes, but it is not the whole truth. It is not the pure light, but simply a certain shade or color of the light.