THEY STICK OUT LIKE SNOWY laundry among the blue-suited bureaucrats and bums of Harvard Square. Irreverently called "towel heads," their children "washcloth heads," the Sikhs move transcendentally through The Square in their white clothes and turbans, bringing their Eastern mysticism to Cambridge's dark-brick, staid Puritanism.

But despite their incongruous and distant appearance, the Sikhs (pronounced "seeks") have taken time from their meditating and yoga, to participate actively in the commercial and spiritual realms of Cambridge and Boston. The 40-member religious group runs Golden Temple Footwear, Golden Temple Restaurant, a carpentry group called Golden Temple Craftsmen, and offers lessons in nutrition, marital counseling, and Kundalini Yoga in their center above Belgian Fudge. They live together in an ashram in Dorchester, a string of four houses, and one of 125 ashrams in America. In the nine years since the ashram's founding they say they have developed a normal and tolerant relationship with their neighbors, who only complain occasionally about their early morning chanting. As one Sikh says, the devotees are "mugged like everyone else."

Mahan Singh, co-director, business manager and Singh Sahib of the ashram seems to have reconciled his faith with the demands of Western society, finding a happy niche like his fellow Sikhs. He sits in the underground Golden Temple Restaurant, munching on a sandwich of sprouts and avocado sauce, drinking yogi tea, and talking very matter-of-factly of his "process of spiritual consciousness" as cars and pedestrians rush overhead. He says he left school like most college graduates to pursue goals he though would bring him happiness; he found a good job and compassionate lover. But he felt incomplete in both. He joined the Peace Corps and lived in western Africa for two years but remained dissatisfied. However, in 1972, he started meditating and was attracted to Sikhism. Today he says, "Nothing in my life I would change. I wouldn't live any other way." A graduate of Harvard Business School, he realizes the advantages of his novel dress, saying his business colleagues "never forget the guy with the turban."

Like his fellow Sikhs, Mahan Singh lives by three simple and rigorous principles. Following the tenet of Nam Japna, he rises at 3 a.m., takes a cold shower and chants the name of God. Living by Dharam di Kirat Karmi, he works hard, living a family-oriented life and striving to live honestly. And he shares his possessions with others and attempts to serve as a model for the community, under the principle of Vanke Chakna. He admits the tenets, especially the last two, are fairly open-ended, and says that many take advantage of their simplicity, affilitiating themselves with the ashram but not devoting their entire spirits and lives to the faith.

But those who do devote themselves entirely to Sikhism must direct both their lifestyles and "consciousness" to the faith. In addition to mediating regularly, Sikhs abstain from tobacco, alcohol, meat, and sex out of marriage. Each wears a kesh, a turban around unshorn hair, as a "crown of spirituality;" a kathera, or special cotton underwear, to "remind" him of his chastity; and a kara, or bangle, to signify commitment to truth and freedom from life's "entanglements." Each Sikh also cariesa kauga, or comb, to symbolize cleanliness, and a small sword called a kirpan to defend neighbors and the family. "We dress alike to stand out and to reaffirm our brotherhood," says Guru Datta Singh Khalsa, a waiter at the Golden Temple Restaurant.

THE LAST OF THE FAITH'S TEN gurus, Guru Gobin Singh, created this khalsa or spiritual brotherhood and prescribed his devotees' dress just before he "left the world" in 1708. He followed a line of gurus dating back to the faith's founder, Guru Nanak, born in northern India in 1469. Nanak saw the hypocrisy of Islam, Hinduism, and the caste system, Mahan Singh says. He says Nanak hoped to turn the tide of the spiritual anarchy by imploring people to bow only before God and to link themselves to the guru. Today, although the faith's chief guru, Siri Singh Sahib, resides at the Sikhs' headquaters in Los Angeles, the Sikhs devote themselves to the scripture of the last living master, the book Siri Guru Granth Sahib. The writings of the ten masters are an account of the faith's traditions and a collection of the chants and songs the first gurus intoned to propel themselves into "a state of ecstasy for God consciousness." Yogi Bhajan, a shortened form of Siri Singh Sahib Bhai Sahib Harbhajan Singh Khalsa Yogiji, translated the scripture into English when he brought the faith to the United States in 1969.

Mahan Singh admits that the counter-culture yearnings of Americans in the late 1960s and early 1970s may account for the faith's early acceptance. But he adds that the growth of the Boston ashram from 15 devotees to more than 40 in its nine years of existence proves that the faith is expanding on its own merits and is not just the product of a rash of discontent and disillusionment with a materialistic and often spiritless society. In addition, Mahan Singh claims the commitment Sikhs must make to the faith discourages most people from seeing it as a fad or passing fancy. "To really experience a higher consciousness," he says, takes "a tremendous amount of commitment and hard work, a desire to heighten your life and your will."

The ascent to this higher consciousness demands the abandonment of an "ego sense of identification," Mahan Singh says. One's consciousness can be seen as analogous to the equation E=mc2, "with the body as the equal sign. You can convert yourself to light or to the gross physical body," he adds.

Yet despite his devotion to Sikhism, Mahan Singh says one may "merge the finite self with the infinite self through many methods. It's just important that you follow the way to the end, take the teaching and follow it to the ultimate."

In the evening, above the ice cream shop, the Sikhs practice the rituals of their predecessors, stretching, contorting, ventilating, and "oaming" to gain the higher consciousness, the ultimate. Below they walk on Mass. Ave. in clean, placidity amidst the chaos. As Siri Guru Granth Sahib says, "As a swan glides upon the water but does not wet its feathers, so a Sikh lives in the world but keeps his mind fixed on God."