According to Serafim Seppälä*, St. Isaac the Syrian understands the perception of the angelic orders to be limited by their own natures.  That is, each rank of the heavenly orders—angels, archangels, thrones, dominions, powers, etc.— is able to perceive a higher rank, but only in so far as its own nature, it’s own ability to perceive God’s glory, allows it.   I admit that this is a rather esoteric observation, one that…