Though Hasidism is not a homogenous philosophy, there are certain ideas common to its many subgroups.
Reprinted with permission from The Jewish Religion: A Companion, published by Oxford University Press.
Hasidism is less a movement with ideas of its own than one in which ideas found in the classical Jewish sources, especially the kabbalah, are given new life and fresh emphasis. The task of discovering in what this emphasis consists is rendered difficult because each of the early masters has his own interpretation of Hasidic doctrine. In some respects, for instance, the teachings of Dov Baer of Mezhirech are at variance with those of Jacob Joseph of Polonoyye, those of Habad different from those of Nahman of Bratslav.
Moreover, the Hasidic works do not normally present their ideas in any systematic form but are in the form of stray comments on biblical verses and talmudic sayings. Students of the movement are consequently obliged to try to note which teachings are common to all the versions and which belong to the particular bent of individual teachers. The Baal Shem Tov (the founder of Hasidism) himself conveyed his ideas in the form of brief aphorisms in Yiddish so that even sayings in Hasidic works that are attributed to the first master come to us at second or third hand and it is often desirable to question their authenticity. The most one can do when describing Hasidic doctrine is seek the ideas that are not found in the Hasidic form in earlier Jewish sources and upon which there is a fair degree of consensus among the Hasidic masters no matter to which they belong. Only with these reservations in mind is it possible to speak of the doctrine of Hasidism.
An idea common to every variety of Hasidism is that of pervasiveness of the divine presence. Behind and in all created things is the divine energy that keeps them in being. The kabbalistic doctrine of the “holy sparks” inherent in all things is laid under tribute [marshalled] in Hasidism to reject asceticism (though a few Hasidic masters did pursue the ascetic way). The ascetic, by abstaining from food and drink and other worldly pleasures, fails to set free the holy sparks clamoring to be released from the demonic forces. The task of the true Hasid is to rescue the holy sparks by engaging in worldly pursuits in a spirit of sanctity. This is the meaning of the older ideal of devekut, “attachment to God” as applied in Hasidism. The Hasid is to have God constantly in his mind even when going about his daily affairs. In a work attributed to Baruch of Meziboz (1757‑1830), grandson of the Baal Shem Tov, it is said that the Baal Shem Tov introduced a new way, without mortification of the flesh, in which the three essentials are love of God, love of the Jewish people, and love of the Torah.
In the earliest period, the masters relied on the doctrine of the “holy sparks” to introduce the teaching regarding “strange [or foreign] thoughts.” When sinful thoughts invade the mind of the Hasid at prayers, the doctrine runs, he should not reject these entirely since even these contain holy sparks to be elevated by thinking of their source on high. For instance, if the Hasid thinks during his prayers of a pretty woman he has met, he should contemplate that her beauty is but a pale reflection of the divine beauty on high, and instead of allowing his mind to dwell on the woman herself, he should see the thought that has entered his mind as calling him to contemplate the spiritual source of all beauty. The staid Mitnagdim (the opponents of Hasidism) were horrified at the very idea which was, in fact, eventually abandoned by the Hasidim themselves on the grounds that only the great masters of the past were sufficiently strong in soul to succeed in elevating the “strange thoughts” without allowing simple lust to obtain lodging in the mind.