Here, if any one lay before us the passage where it is said, “Blessed are the pure in heart, for they shall see God,” from that very passage, in my opinion, will our position derive additional strength; for what else is seeing God in heart, but, according to our exposition as above, understanding and knowing Him with the mind? For the names of the organs of sense are frequently applied to the soul, so that it may be said to see with the eyes of the heart, i.e., to perform an intellectual act by means of the power of intelligence. So also it is said to hear with the ears when it perceives the deeper meaning of a statement. So also we say that it makes use of teeth, when it chews and eats the bread of life which comes down from heaven. (Book I, Part 9)

How do we perceive? How do we know?

We have clear evidence our sensory observations -- and our mental interpretations of those observations -- can be mistaken.

Our mental interpretations of reality are especially undependable when our angle of physical observation is limited, obscured, or purposefully manipulated.

We know that two equally attentive and capable individuals can in good faith observe the same event, describe it differently, and discern very different meaning from it.

If our concept of God as beyond time and space, ultimately transcendent, and profoundly powerful has any validity at all, what is our capacity -- using senses, intellect, or any other skill -- to fully apprehend God? Very modest.