The Hasidic movement started through the activities of a particular person in a well-defined place and time. The founder of the movement, Rabbi Israel Ball Shem Tov ("Besht") lived in Eastern Europe in the 18th century. He died in 1760 and his disciples then disseminated his teachings far and wide.
Other contemporary prominent Jewish leaders include Rabbi Eliyahu from Vilna (the "Gaon") and Moses Mendelssohn. Both passed away before the turn of the century (though they were younger than the Besht). In some way, those aforementioned Jewish leaders still have their respective following to this very day. Mendelssohn represents the "rational" school of Judaism as exemplified by its Reform and Conservative segments. The Gaon represents the Litvish/Yeshivish world and the Besht represents the Hasidic world.
Nobody, however, sees any connection between those movements beyond the coincidence that they originated in the 18th century, which begs the question: is it really a mere coincidence that all the major modern Jewish segments have their origin in the cultural milieu of 18th centruy Europe? What really transpired in 18th century Europe that can perhaps shed some light on the essential impetus for the launching and development of those movements?
Historians, of course, know the answer. It's the Enlightenment. Two very important events occurred in the 18th century. The American Revolution and the French Revolution. Both these events had a tremendous impact on the future direction of Western Civilization. At the turn of the 18th century people everywhere were grappling with situations and questions with which they had never come face to face before. Is the monarch sanctioned by God? Does the clergy have a monopoly on Godly matters? What if God's word as expounded by the priest does not make sense to me? Am I allowed to interpret the word as I see fit? Is government a holy institution that one may not impugn or all hell will break loose, or is it possible -- just possible-- that government is merely a social contract of "live and let live" (first propounded by Thomas Hobbes)?
I think that a historical anchor exists in the 18th century and its people, perplexed and shaken to the core by those very profound questions, to many of the modern social and religious movements, especially Hasidism.
You see, most people tend to think that Hasidism is a populist and regressive movement. Folks who were brutish and uneducated, who toiled hard and saw little reward, who sought to liven up God and tailor God to their needs: a God who appreciated song, dance and prayer just as much as he does scholarship, erudition and punctilious observance of Mitzvot. But this view is now brought into question since Hasidism has now matured far beyond its incipient age of dance and music and is now de rigueur in the Haredi world. There is hardly any Haredi (Ultra-Orthodox) person in our society that is not directly or indirectly inspired by Hasidism. Of course, we all know that modern Hasidism is more nuanced and complex than that of 18th century Europe. But ultimately the question beckons: what legitimates this movement? What's the secret to its enduring appeal and why is it so important in the survival of Haredi Judaism?
So let's go back and re-interpret 18th century events in the light of our time. As pointed out earlier, the 18th century was an era of upheaval; not just militarily or politically but also culturally and religiously. There were essentially two categories of answers offered in response. One was conservative and God-centered and the other was progressive and humanistic. The wealthier and educated world, often characterized by inhabiting Western Europe, often chose the latter, whereas the people of lesser means, intellectually and materially often chose the former.
Why? Re-evaluating one's morals is a very difficult task. It is often easier to effect impressive technological breakthrough, than redesign one's moral framework. It's just too depressing, too wrenching, too discouraging -- to propose that the guardian angel, once thought to accompany the human on every step of their lives through divine providence, is in fact just an illusion. The enlightenment suggested that there is no magic bullet. There is no God who is there for you for your every need and want listening and granting your prayer and who will not hang you out to dry. The enlightenment suggested that humans are running the show and humans need to assume responsibility for their own lives. Again, assuming responsibility and the uncertainty that such an attitude towards life encompasses, is gut-wrenching. It could be highly distressing unless the individual has the capacity and willingness to grab the bull by the horn and make tough, independent, fateful decisions. It is so much easier to hang on to "God" and "know" that God will be there for you no matter what.
This concept constitutes the watershed between the original Hasidic camp and the Mendelssohn camp. Hasidim sought to avoid learning, discovering and rebuilding from scratch and so they latched on to God. The Mendelssohn folks asked the tough questions and therefore ultimately found themselves in a secular world. It's not that the Mendelssohn disciples made a conscious decision to abandon their faith or to disavow their God. The original Mendelssohnians were in fact very pious Jews. What defined them is one thing: the capacity and desire to learn, to absorb and to process information. The Hasidim, in contrast, expressly denounced scholarship and elected retrenchment as their modus operandi to deal with the enlightenment crisis.
The reason that modern ultra-orthodoxy is so closely affiliated with Hasidism is that to this very day one must shut out the inquisitive and investigative process in order to preserve one's faith. Hasidim were the ones who provided the archetypal paradigm for all future generations to follow in this regard. This explains the strange and ironic phenomenon that at the time Hasidim were seen as dangerous to tradition since they often did not rigorously observe halakha, whereas nowadays they are seen as the stalwarts of faith, observance and piety. It's not about halakha; it's about asking questions. The original Hasidim lived in a setting where they were incapable of asking questions, much less answer them in a satisfactory manner; so they developed song and dance and psalm-recitation as wonderful emotional panacea to the intellectual turbulence of the time. The modern Hasid likewise shuts out the rational process but since he is a bit more sophisticated, he manifests a greater adherence to halakha and declares a stronger commitment to scholarship. Ultimately, however, his "scholarship" is spurious since he only entertains the kind of questions that are consistent with his faith and preconcieved religious notions.
Hasidism is thus NOT simply a regressive movement; a movement that is bound to vanish in due time, as progress inevitably triumphs over regress. It is, rather, a unique school of thought; a different way of coping with the socio-religious upheaval of the time. It's the "don't-ask-questions" mode of coping. It's the emphasis of emotional aspects of Judaism over intellectual ones. Hasidism survives in modern society insomuch as this blind, uncritical, unquestioning reliance on tradition is so critically important to modern Ultra-Orthodoxy. Orthodoxy desperately needs blind faith like a fish needs water.
In contrast, those who did not restrict their thought processes, EVEN THOUGH THEY HAD THE HIGHEST REGARD FOR THEIR FAITH (Mendelssohn and his followers), eventually found themselves reforming and rationalizing their way out of the system altogether.