כי מי שדעתו יפה לדעת את ה׳ ולהתבונן בגדולתו יתברך
The first level is that of a person discerning enough to know G‑d and to reflect on His greatness,
ולהוליד מבינתו יראה עילאה במוחו, ואהבת ה׳ בחלל הימני שבלבו
and to create out of his understanding a lofty fear in his mind and a love of G‑d in the right part of his heart (the seat of the divine soul's emotions),
להיות נפשו צמאה לה׳ לדבקה בו
so that his soul thirsts for G‑d [seeking] to cleave to Him
על ידי קיום התורה והמצות, שהן המשכת והארת אור אין סוף ברוך הוא על נפשו לדבקה בו
by fulfilling the Torah and mitzvot, which are the extension and illumination of the Ein Sof-light upon one's soul by which one may cleave to Him.
In other words, this person's desire to cleave to G‑d through the only means of doing so, viz., Torah and mitzvot, stems from a love and awe of G‑d created by intellectual appreciation of His greatness. His kavanah in mitzvot (i.e., his desire to cleave to G‑d through mitzvot) thus has an intellectual basis.
ובכוונה זו הוא לומד ומקיים המצות, וכן בכוונה זו מתפלל ומברך
When he studies [Torah] and fulfills the mitzvot [it is] with this kavanah, and likewise when he prays and recites blessings [it is] with this kavanah of cleaving to G‑d Whose greatness he has come to understand.
הרי כוונה זו על דרך משל כמו נשמת המדבר, שהוא בעל שכל ובחירה, ובדעת ידבר
Such kavanah is analogous to the soul of a human being, who possesses intelligence and freedom of choice and who speaks with wisdom, for such kavanah is likewise based on intellect and choice.
ומי שדעתו קצרה לידע ולהתבונן בגדולת אין סוף ברוך הוא
The second level of kavanah is that of a person whose understanding is too limited to know and to reflect on the greatness of the blessed Ein Sof,
להוליד האהבה מבינתו בהתגלות לבו, וכן היראה במוחו, ופחד ה׳ בלבו
so as to create out of his understanding a revealed love in his heart, and also awe in his mind and dread of G‑d in his heart. His level of understanding is inadequate to create a palpable spiritual emotion.
Since one's observance of the mitzvot is contingent on love of G‑d, and refraining from sin is contingent on fear of G‑d, how can one who cannot evoke these emotions because of his limited understanding fulfill the Torah and mitzvot? What motivates him?
Such a person, the Alter Rebbe will say, is motivated by his arousal of the "hidden love," the love of G‑d (which also comprises an aspect of fear) hidden in the heart of every Jew.
Even if he cannot arouse this love to a revealed state, where he can actually feel this love (and fear) in his heart, he can surely arouse it in his mind, so that at that level he will experience a conscious desire to attach himself to G‑d. This desire will lead him to study Torah and fulfill the mitzvot, since this is the only way for him to realize his wish.
In this case, his kavanah in Torah study and in mitzvot (i.e., his desire to cleave to G‑d) is based on "instinct", i.e., on the innate love of G‑d found in his heart. This level of kavanah therefore resembles the soul of an animal, whose actions are instinctive, not rational.
In the Alter Rebbe's words:
רק שזוכר ומעורר את האהבה הטבעית המסותרת בלבו
He merely recalls and arouses the natural love hidden in his heart,
ומוציאה מההעלם והסתר הלב אל הגילוי במוח, על כל פנים
and brings it out of concealment in his heart to a state of consciousness, in his mind at least (even if he cannot arouse a revealed feeling of love in his heart, surely he can summon it to mental consciousness),
שיהיה רצונו שבמוחו ותעלומות לבו מסכים ומתרצה בריצוי גמור באמת לאמיתו
so that his will in his mind and in the recesses of his heart should approve and consent, with complete willingness and perfect sincerity
למסור נפשו בפועל ממש על יחוד ה׳
to surrender his life in martyrdom, in actual fact (not merely as a figure of speech), for his affirmation of the unity of G‑d (rejecting belief in any other divinity),
כדי לדבקה בו נפשו האלקית ולבושיה, ולכללן ביחודו ואחדותו
in order to attach to Him his divine soul and its garments of thought, speech and action, and to unite them with His unity —
שהוא רצון העליון המלובש בתלמוד תורה וקיום המצות, כנ״ל
which is identical with the Supernal Will that is clothed in Torah study and performance of the mitzvot, as explained above.
Like martyrdom that one undergoes out of love for G‑d, study of the Torah and performance of the mitzvot unite the soul with G‑d. Therefore, one's arousal of his natural love of G‑d (to the point where he is prepared to offer his life for G‑d's unity) will also motivate him to fulfill the Torah and mitzvot.
וגם היראה כלולה בה, לקבל מלכותו, שלא למרוד בו, חס ושלום
This [natural love] also comprises fear [of G‑d]: acceptance of His dominion, so as not to rebel against Him, G‑d forbid, through sin.
ובכוונה זו הוא סר מרע ועושה טוב, ולומד ומתפלל ומברך
When, motivated by this kavanah (which is born of his innate love and fear of G‑d), one "turns away from evil" (by refraining from sin) and "does good" (by observing the mitzvot), and studies, prays, and recites the blessings,
בפירוש המלות לבדו, בלא דחילו ורחימו בהתגלות לבו ומוחו
thinking merely of the meaning of the words, without conscious love and fear of G‑d in his heart and mind, which would lend emotional intensity to his prayer; lacking revealed love and fear, he prays only with the meaning of the words; when one fulfills the Torah in this manner,
הרי כוונה זו, על דרך משל, כמו נשמת החי שאינו בעל שכל ובחירה
this level of kavanah is analogous to the soul of an animal, which possesses neither intelligence nor freedom of choice,
וכל מדותיו, שהן יראתו מדברים המזיקים אותו ואהבתו לדברים הנאהבים אצלו, הן רק טבעיים אצלו, ולא מבינתו ודעתו
and whose emotions — its fear of harmful things and its love of pleasing things — are merely natural to it, not a product of its intelligence or understanding.
וכך הן, על דרך משל, היראה והאהבה הטבעיות המסותרות בלב כל ישראל
So, too, by way of example, are the natural love and fear hidden in the heart of every Jew; they, too, are not a product of intelligence or choice,
כי הן ירושה לנו מאבותינו, וכמו טבע בנפשותינו
for they are our inheritance from our Patriarchs, and are like a natural instinct in our souls,
כנזכר לעיל
as mentioned above, in ch. 18.
The Alter Rebbe explained there that the Patriarchs bequeathed to their descendants as an eternal inheritance, a divine soul with an intrinsic love (and fear) of G‑d. Because this love is merely instinctive and natural, its function as motivation (kavanah) for the fulfillment of Torah and mitzvot is likened to the soul of an animal.
To summarize: Both the performance and kavanah of mitzvot are divided into two categories.
The two levels in performance (the "body" of the mitzvot) are analogous to the two classes of "body"-creatures — inanimate beings and plants. They are (a) mitzvot performed with action and (b) mitzvot performed through speech or thought.
The two levels in kavanah (the "soul" of the mitzvot) correspond to the two classes of "soul"-creatures — animals and man. They are: (a) kavanah generated by one's intellectual contemplation of G‑dliness, and (b) kavanah arising from one's natural love (and fear) of G‑d.
