The main strictures which the Mithnagdim leveled against the Beshtian doctrines centered on two points:
Firstly, the teachings of the Ba'al Shem Tov accorded especial esteem to the prayers and Tehillim-recital of the unlearned and untutored Jew, even though he did not know what he was saying. This attitude, the Mithnagdim contended, tended to give the am ha'aretz and ignoramus a sense of undeserved self-importance, and lowered the prestige of the talmidei-chachamim. It seemed to ignore the Talmudic saying that "all calamities that occur in the world are due to the amei-ha'aretz."
Secondly, according to the doctrine of the Ba'al Shem Tov, even a Gaon and Tzaddik have to serve G-d in the way of Teshuvah. The Mithnagdim took strong exception to this doctrine, arguing that it placed the sainta nd scholar in the category of ordinary sinners and repenters. Such a notion surely undermined the honor of the Torah and the dignity of the talmidei-chachamim. The Mithnagdim further concluded that this notion was in contradiction to the view of the Torah, Written and Oral, which described the Tzaddik as the "foundation of the world" and the talmidei-chachamim as those who "increase peace in the world" and as the true "builders" of the Jewish nation. The Beshtian notion of requiring them, too, to do penance was humiliating, and most objectionable.
Rabbi Schneur Zalman replied to the said two main contentions of the Mithnagdim as follows:
"The basis of the doctrine of the Ba'al Shem Tov and of the teachings of his successor, my teacher and master the Maggid of Miezricz, which illuminate the way of Divine service, followed by all the disciples of our master the Maggid, is to be found in the first Divine revelation to Moshe Rabbeinu.
"My teacher, the Maggid of Miezricz, taught me the following doctrine, which he had received from the Ba'al Shem Tov:
- It is written, "And the angel of God appeared (vayyera) unto him in a flame of fire from the midst of the bush. And he saw that the bush was burning with fire, but the bush was not consumed. Then said Moshe, 'I will turn aside and see this great sight" (Exod. 3:2-3).
The Targum renders the word vayyera ("appeared") by v'itgali ("revealed himself"). The meaning of "revelation" is that it comes within the perception of everyone, to each one according to one's capacity, down to the lowest levels. Thus, the Targum also renders the word vayyered in Exod. 19:20 ("And G-d came down on Mount Sinai") by v'itgali ("revealed himself"), though elsewhere, e.g. Gen. 38:1 ("And Judah came down"), the word vayyered is rendered by v'nahat ("descended"). Similarly in Gen. 11:5 the Targum gives a corresponding rendition in the sense of "revelation," as in the case of the revelation at Mt. Sinai.
Now, just as the revelation at Sinai was intended for all the people, from Moshe down to the Jew of the most humble station, so must "revelation" be understood in the other instances, including the first revelation to Moshe out of the Burning Bush. Here, too, we must assume a revelation which can be perceived on all levels, down to the lowest, as already mentioned.
The words b'labat esh are rendered by Rashi by b'shalhevet shel esh, libo shel esh ("in a flame of fire; the heart of fire"). Thus, the message of G-d (i.e. "G-dliness") is to be found in the "heart of fire," i.e. in the earnest and sincere inwardness of the heart, where the fiery embers of G-dliness abide.
The words "from the midst of the bush" elicit Rashi's further commentary: "But not from another [more stately] tree, alluding to the verse, 'I am with him in distress (tzarah)'" (Ps. 91:15). Tzarah (literally "narrow place") alludes to this material world, which is so called because it is limited in space; and also because the Light of the En Sof is concealed therein in Nature, and is thus "confined" and "constricted," as it were. By contrast, the supernal worlds, where the Light of the En Sof shines forth manifestly, are called "wide, open spaces."
However, the design and purpose of the creation of this physical world is to illuminate it and convert it from צרה to צהר- "light"- by means of the light of the Torah and the Mitzvoth, to be studied and observed in the daily life.
It is written, "Man is like a tree of the field" (Deut. 20:19). There are fruit-bearing trees, to which, according to Rabbi Yochanan, the talmidei-chachamim are likened (Taanit 7a); and there is the sneh, a humble bush that bears no fruit. Yet the "fiery flame" was manifest in the sneh. To be sure, the talmidei-chachamim, the students of the Torah, are filled with fire, since the Torah is called "fire" (Deut. 33:2), but it is not the inextinguishable kind of fire which burned in the sneh. The talmidei-chachamim can, and do, quench their inner fire by the intellectual gratification which they derive from their Torah studies, from the new insights which they discover, and from original innovations in the interpretation and exposition of the wisdom of the Talmud.
Not so the ordinary and unlearned Jew, the sneh- in whom burns an inextinguishable fire, and unquenchable longing for attachment to G-d. The only spiritual expression that the simple and untutored Jew can find, is in prayer and the recital of Tehillim. And though he may not know the exact meaning of the sacred words he intones, they contain the full force of his sincerity and wholeheartedness.
The only motivation of these humble Jews is their simple faith in G-d, which creates in them the burning and insatiable desire for Torah and Mitzvoth, a desire which, of necessity, remains unsatisfied and unquenched.
That is why the eternal "fiery flame" (labat esh) is to be found precisely in the hearts of these simple, sincere folk.
It is written, "And Moshe said, 'I will turn and see this great sight'" (Exod. 3:3) which, according to Rashi, means "I will turn from here, to come closer to there." This indicates that Moshe Rabbeinu understood the Divine message of the Burning Bush which emphasized the unique quality of the ordinary Jew- the Labat esh being found precisely in the sneh, rather than in the cedars of Lebanon. The realization of this evoked a sense of Teshuvah in him, and a change of outlook and direction ("I will turn [ashuva] from here to come closer there").
Now, Moshe Rabbeinu was a perfect Tzaddik. The course of Teshuvah of the perfect Tzaddik is quite different from that of the ordinary repenter. It is effected in the manner of "I will turn from here to come closer there." In other words, no one, not even the greatest Tzaddik, should be static in his Divine service, however perfect it may seem at any time. There must be a constant striviting toward ever greater heights, turning from one high level to a still higher one, with a constant desire to get closer to G-d. In this progression, which is essentially an infinite process, each higher level attained leaves the previous level, however satisfactory it seemed previously, deficient by comparison. Hence there is room for Teshuvah even for the perfect Tzaddik."
Rabbi Schneur Zalman emphasized that the said fundamental tenets of the Ba'al Shem Tov were based on the first Divine revelation to Moshe Rabbeinu, whom G-d had chosen to be the first deliverer and leader of the Jewish nation and he went on to explain the precedental nature of that revelation:
The Divine revelation to Moshe Rabbeinu was quite different from the Divine revelation to Noah, or even to Abraham. For the Divine revelation to Noah was a personal one, due to special Divine grace. Whether Noah was singled out for this Divine love because "Noah found favor in the eyes of G-d" (Gen. 6:8), or because he actually merited it, as it is written, "For I have found thee righteous before Me in this generatoin" (ibid. 7:1), it was, nevertheless, a personal revelation, confined to him only.
The Divine revelation to Abraham was quite different. It contained certain instructions as to Divine service, and was attended by extraordinary tests and trial. It was, obviously, on an altogether higher level, though it, too, came as a result of special Divine love, as it is written, "For I know him (Rashi: love him) that he will command his children and his household after him, that they observe the way of G-d, to do righteousness and justice," (Gen. 18:19). In the Midrash Abraham was also called the "Supreme King's favorite" (B.R. ch. 42). Be it as it may, G-d's revelation to Abraham was also, essentially, a personal one.
However, the Divine revelation to Moshe Rabbeinu- Rabbi Schneur Zalman explained- was not merely a personal one, but rather a general one, serving as a guideline for all future leaders of our people. This revelation showed that a Jewish leader should look for the labat esh in the sneh- among the ordinary people. The leader must try to discover this spark in the heart of the simple folk and fan it into an all-consuming flame.