"Despite Eckhart's longtime reputation as an honorary Protestant and his enthusiastic reception among nineteenth-century Romantics and Idealists, mainstream Protestants, particularly German Lutherans, have been slower to embrace the master fully because of his association with "Catholic" mysticism. The great church historian Adolf von Harnack (1851-1930) proclaimed that "mysticism can never be made Protestant without slapping history and Catholicism in the face." As theologian Karl Barth (1886-1930) argued, mysticism propagates a path to salvation "that completely bypasses the biblical history of salvation and the Last Days." Since the 1960's Protestant believers have been worried less by the Catholic context of Meister Eckhart and other mystics than by the latter's growing association with several New Age – and presumably unscriptural – approaches to enlightenment. That cautiousness continues today, although many American Protestants, including evangelicals, are increasingly discovering worthwhile spiritual insights in the words of the medieval master.
Most commonly since the mid-twentieth century, the master has been praised as a bridge to Asian religions and philosophies. In his correspondence with Thomas Merton, Japanese scholar D.T. Suzuki (1870-1966) called Eckhart "the one Zen thinker of the West." The just man's inner Christ nature described by the medieval master looks remarkably similar to the internal Buddha nature of Mahayana tradition, as does Eckhart's combination of the contemplative-active life of love. Letting-go-ness lines up nicely wiht Zen "no-mind" (wuxin) as well as the Taoist "no action" (wuwei). The Buddha also remained wary of human God-talk and aspired to a unity with the ultimate similar to Eckhart's deification. The many resemblances are indeed striking.
Several modern observers have also notes Meister Eckhart's kinship with parts of the Hindu Tradition, particularly the Advaita Vedanta school. The Tamil writer Ananda K. Coomaraswamy (1877-1947) exlaimed that "Eckhart's sermons might well be termed an Upanishad of Europe," noting the master's "astonishingly close parallel to Indian mods of thought; some whole passages and many single sentences read like a direct translation from Sanskrit." Here too, some Eckhatian terms seem to have other religious equivalents, such as Brahman for the ground, and neti-neti (not his, not that) for the ineffability of the divine mystery. Above all, both Eckhart and the Vedanta school emphasize the necessity of intuition to experience the entirely of reality, which then leads to loving kindness.
Both Islam and Judaism also have their own strong mystical traditions, and here too many notable similarities to Meister Eckhart's teachings emerge. Like Eckhart, his near contemporary, the great Sufi master Ibn Arabi (1165-1240) sought a religious philosophy that would above all be practical for genuine spiritual seekers. His Perfect Human, like Eckhart's Just Man, has realized the divinity within – the inseparableness from the divine essense in the eternal Now – and has dedicated himself or herself to a life of perfect love. The fantastically popular Sufi poet Jalal ad-Din Rumi (107-73) prefigures his Christian counterpart's language and message even more strikingly. With evocative images and meticulously crafted phrasing, Rumi describes his own relentless pursuit of union (fana) with "the Beloved." The experience of this mystery, which most non-Sufis reject as heretical, is like no other. Coincidentally, a Jewish contemporary of Eckhart and Rumi, the mystic philosopher Abraham Abulafia (140-91) taught a similar kind of divine union, known as mediative Kabbalahism, which remaines likewise controversial among modern Jews.
Meister Eckhart's seemingly universal applicability among virtually all the world's religions accounts for his particularly popularity in the rapidly growing belief in religious syncretism, also known as perennialism (and sometimes called religious pluralism). This is the conviction that all the world's religions share a common essential truth, which has since been fractured into various rituals, doctrines, and other structures. Given that Meister Eckhart in fact sough such a universal religious philosophy, it's little surprise that he has proven such a superstar among its adherents. The Neoplatonist Agostino Steuco (1497-1545) coined "perennial philosophy," to describe a common, transcendent truth evident in both classical Greek philosophy and later religious traditions. Steuco's idea lay largely dormant until spreading among the Deists of hte eighteenth century and even more spectacularly among the Transcendentalists, Universalists, and Theosophists of the nineteenth century. In 1945, Aldous Huxly (1894-1963) published The Perennial Philosophy, in which Eckhart plays a prominent role, taking the universalist perspective into popular culture. Since then, perennialism has become closely associated with various New Age writers as well as some ecumenists among Christian denominations.
At least on the surface, Eckhart could qualify as the patron saint of the perennial movement. Like its modern advocates, he rejected the materialism of human society to seek a hidden, spiritual truth. He was also remarkably inclusive in his sources for past wisdom, consulting not just Christian thinkers, but also Jews, Muslims, and ancient pagans. Although a Christian (and member of the clergy!), he stressed individual, internal transformation over external rituals or doctrines. His approach was egalitarian, not requiring a high degree of learning or other special gnosis. And above all, his sermons were practical and encouraging, full of colorful metaphors, memorable aphorisms, and answers to anticipated questions. There was but one goal, union with God, which modern followers refer to as ultimate reality – and Eckhart would not disagree with the characterization."
– Joel F. Harrington, Dangerous Mystic