The Active Intellect by Rabbi Yehudah Ashlag (Ba’al ha-Sullam)
It is written, “Every man is obligated to grasp the root of his soul.” Meaning the ultimate desire and hope of those created is דְבֵקוּת (devequt), cleaving, to His qualities, may His great Name be exalted: “[Abba Shaul said:] Just as He is [gracious and] compassionate, so you [be gracious and compassionate]” (BT Shabbat 133b). And His qualities are the holy sefirot as is known, and this is the mystery of שֶׂכֶל הַפּוֹעֵל (sekhel ha-poel), the Active Intellect, that guides His world and gauges His effluence and goodness for them, blessed be He.
But we must understand why this is called, “cleaving to the Creator,” for behold: seemingly this is merely לִמּוּד (limmud), study. I shall explain by way of parable: Within any action in the world, the actor’s intellect inheres in that action. Just as in a table one can grasp a facet of the intellect of the carpenter, his dexterity and the deftness in his craft, whether great or small, since in the course of his work he assessed it in terms of the qualities of his intellect. And he who looks at the result, apprehending the intellect that is “buried” there, cleaves to that very intellect which acted upon it—they literally unite—because there is no distance or separation between הַרוּחָנִיּם (ha-ruḥanim), what is immaterial, even with separate bodies; the intellect inhering there cannot be separated, for what knife can cut the immaterial off? Rather, the essential difference between immaterial things [or: spiritual matters] lies in their qualities, praiseworthy or blameworthy, but also in diversity. For the intellect reckoning astrology will not cleave to the natural sciences. And even in science itself great diversity is discovered. Since one [branch] rises over another even in a single [field of] science, and only through this does the immaterial separate. But when two sages contemplate a single science and bear the same stature of intellect, then they are united, literally, for what separates them?
So when one is found contemplating another’s action, grasping the intellect of the sage who performed it, both are gauged by one power and intellect. Now they are actually united, like a man who bumps into his beloved friend in the market: he embraces him and kisses him, and it is impossible to severe the bond between them. Hence, the general principal is that on the human [rung of existence], the power of the intellect is best suited to mediate between the Creator and His creatures. That is, He emanated a single spark from this [mediating] power. Through that spark, all returns to Him.
[How many are Your works, O YHWH!] All of them You made in wisdom; [the earth is filled with Your creatures] (Psalms 104:24)—He created the whole world in His wisdom. Hence, he who is rewarded with attaining the אוֹפַנִּים (ofannim), circuits, by which He created the world and its order, behold: he cleaves to the Intellect that acts upon them, he cleaves to the Creator. And this is the mystery of “The Torah is all names of the blessed Holy One,” which belong to the creatures. And through their merit, the creatures grasp the Intellect that acts upon all, since the Creator gazed upon the Torah when He created the world, as is known [see Zohar 2:161b]. He who attains enlightenment by way of Creation forever cleaves to that Intellect. Thus, he cleaves to the Creator, blessed be He.
In this sense the blessed Holy One has shown us His artisan’s tool—[however] must we create worlds? Yet from what has been said here, [we understand] the Creator has shown us His order that we may know how to cleave to Him, which is cleaving to His qualities.