This last aspect — the fact that God is utterly in control of everything — is addressed in this section of Klach as well, as when Ramchal says right at the beginning of Petach 1 that “The Infinite One’s Yichud” implies that only His will functions (fully) and that no other will functions other than through it. Hence, He alone reigns (supreme) and no other (being’s) will does”, and when he points out in his comments there that “everything that we see” and experience “has but one Lord”, God Almighty; that He “alone carries everything out, and controls everything”.
So there are two aspects of God’s Yichud — which we’d define as His “uniqueness” in these contexts: first, His being the only entity who simply must exist if anything else is to; and second, His being utterly in control of everything.
But there’s a third and rather arcane aspect to God’s Yichud as well which Ramchal alludes to at the very end of this section where he says that in the end “God’s Yichud will thus be revealed, (the experience of) which will in fact be the delight of the souls. As we’ll see, this alludes to another definition of Yichud, utter “oneness”, but not in terms of His being the only God.
He referred to this elsewhere when he said that “God wants to reveal His Yichud and to thus show that ‘I (God) am first, yea I am last’ (Isaiah 48:12), that … all curses will be turned into blessings and all wrong will return to right” . Let’s follow this trend of thought.
 Iggrot Pitchei Chochma v’Da’at p. 404.
(c) 2010 Rabbi Yaakov Feldman
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