Blake frequently uses the word 'behold' to indicate an intense sort of seeing in which the attention is fixed upon the object. Biblical scholars note that 'behold' is used in this way in the Old and New Testaments. Blake's statement that 'If the doors of perception were cleansed every thing would appear to man as it is: infinite', refers to the same ability to see as he means by 'behold'.
 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
 And looking upon Jesus as he walked, he saith, Behold the Lamb of God!
To invest oneself in the object of perception opens one to the possibility of transformation. Perception becomes a reciprocal relationship in which object and perceiver each influence the other.
Los is transformed as he beholds Urizen becoming a separate entity as the sensory organs developed. Los responds as the 'red Round Globe' separates into a female and the male form follows. In this instance the negative activity which is beheld leads to further splitting and deconstruction.
Yale Center for British Art
Book of Urizen
Milton, Plate 3, (E 97) "Enraged & stifled without & within: in terror & woe, he threw his Right Arm to the north, his left Arm to the south, & his Feet Stampd the nether Abyss in trembling & howling & dismay And a seventh Age passed over & a State of dismal woe Terrified Los stood in the Abyss & his immortal limbs Grew deadly pale; he became what he beheld: for a red Round Globe sunk down from his Bosom into the Deep in pangs He hoverd over it trembling & weeping. suspended it shook The nether Abyss in temblings. he wept over it, he cherish'd it In deadly sickening pain: till separated into a Female pale As the cloud that brings the snow: all the while from his Back A blue fluid exuded in Sinews hardening in the Abyss Till it separated into a Male Form howling in Jealousy"
In Jerusalem we learn that beholding the Eternal Vision is what maintains the continued existence of the human.
Jerusalem, Plate 34 , (E 179)
"Turning from Universal Love petrific as he went, His cold against the warmth of Eden rag'd with loud Thunders of deadly war (the fever of the human soul) Fires and clouds of rolling smoke! but mild the Saviour follow'd him, Displaying the Eternal Vision! the Divine Similitude! In loves and tears of brothers, sisters, sons, fathers, and friends Which if Man ceases to behold, he ceases to exist:
The divided man is incompatible with the Eternal Vision and becomes screened off in the
darkness of the void. The Eternals protect themselves from viewing the divisions by erecting curtains to avoid beholding the distorted universe created by Urizen.
Urizen, Plate 18,(E 78) "9. All Eternity shudderd at sight Of the first female now separate Pale as a cloud of snow Waving before the face of Los 10. Wonder, awe, fear, astonishment, Petrify the eternal myriads; At the first female form now separate PLATE 19 They call'd her Pity, and fled 11. "Spread a Tent, with strong curtains around them "Let cords & stakes bind in the Void That Eternals may no more behold them" 12. They began to weave curtains of darkness They erected large pillars round the Void With golden hooks fastend in the pillars With infinite labour the Eternals A woof wove, and called it Science"
The opposite movement is produced by beholding 'the good, the true and the beautiful' as Paul advises us to do in Philippians:
 Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.
Milton, PLATE 13 , (E 106) "For then the Body of Death was perfected in hypocritic holiness, Around the Lamb, a Female Tabernacle woven in Cathedrons Looms He died as a Reprobate. he was Punish'd as a Transgressor! Glory! Glory! Glory! to the Holy Lamb of God I touch the heavens as an instrument to glorify the Lord! The Elect shall meet the Redeem'd. on Albions rocks they shall meet Astonish'd at the Transgressor, in him beholding the Saviour. And the Elect shall say to the Redeemd. We behold it is of Divine Mercy alone! of Free Gift and Election that we live. Our Virtues & Cruel Goodnesses, have deserv'd Eternal Death. Thus they weep upon the fatal Brook of Albions River." Jerusalem, Plate 34 , (E 179) "Turning from Universal Love petrific as he went, His cold against the warmth of Eden rag'd with loud Thunders of deadly war (the fever of the human soul) Fires and clouds of rolling smoke! but mild the Saviour follow'd him, Displaying the Eternal Vision! the Divine Similitude! In loves and tears of brothers, sisters, sons, fathers, and friends Which if Man ceases to behold, he ceases to exist: Saying. Albion! Our wars are wars of life, & wounds of love, With intellectual spears, & long winged arrows of thought: Mutual in one anothers love and wrath all renewing We live as One Man; for contracting our infinite senses We behold multitude; or expanding: we behold as one, As One Man all the Universal Family; and that One Man We call Jesus the Christ: and he in us, and we in him, Live in perfect harmony in Eden the land of life, Giving, recieving, and forgiving each others trespasses. He is the Good shepherd, he is the Lord and master: He is the Shepherd of Albion, he is all in all, In Eden: in the garden of God: and in heavenly Jerusalem. If we have offended, forgive us, take not vengeance against us. Thus speaking; the Divine Family follow Albion:"