"Samurai!" at the Museum of Fine Arts, Boston A lot of good-looking things were created for bad reasons: to package politics, justify violence, make some men seem mighty and others weak. A visit to an art show can be a delight, but also a walk through blighted history. As an example, consider "Samurai! Armor From the Ann and Gabriel Barbier-Mueller Collection" at the Museum of Fine Arts here, a stellar display of exquisite combat hardware. As a class of career warriors, samurai (or bushi) took nascent form in Japan in the eighth century A.D., when existing methods of organized warfare weren't working. The imperial army, made up largely of conscripted peasants, was having no luck subduing separatist tribal groups. So the government turned to regional militia bands to finesse the matter. These forces, formed by provincial clan leaders, were basically private protection societies, miniature armies, adept at equestrian skirmishes. And although competitive with one another, they quickly saw the wisdom of forging strength-in-numbers bonds. As their collective power grew, imperial power receded. By the 12th century, Japan was fully in the hands of an armed elite, headed by leaders called shoguns, for whom samurai worked. Over time, this samurai society, formulated a self-defining ethos known as bushido, or "the way of the warrior," based on an idealizing code of conduct for living and for dying (ritual suicide was preferable to dishonor), with Confucian and Buddhist overlays. Simultaneously, a new visual culture evolved, one that blended extremes of brutality and delicacy, as if justifying one with the other. For centuries, the samurai had their work cut out. War was constant, its form gradually changing. Early on, equestrian archery was the preferred mode. Later, the use of massed infantry came into favor and swords became the chief weapon, followed eventually by firearms introduced from Europe (or from China, depending on the source you read). With shifts in military campaign style came adjustments in defensive technology. For every situation, suits of armor were designed: light and flexible for cavalry encounters; heavy and encasing for warding off sword blows on the ground. And astonishing things these head-to-toe containers were: exaggerated versions of layered-look fashion, a species of mechanical couture with detachable parts. One of the almost two dozen complete suits of armor in the show - all on loan from the Ann and Gabriel Barbier-Mueller Museum in Dallas - was made around 1600 for a member of the Mori clan, a landholding family, and is still (this is rare) intact. Its basic sartorial components included shoulder guards, shin guards, sleeves, thigh protectors, a skirt and a chest protector, along with a helmet, gloves, mask and boots, and a cushioning layer of silk underwear. In addition, it comes with a range of indispensable accessories, among them two swords, a longbow and quiver of arrows, a selection of hats, a military baton, a fireproof coat and a large folding fan, ornamented with a big-red, rising-sun dot. Organizing and dressing must have been a production. When certain suits of armor are fully assembled, they look like portable fortresses. They give the same impression of ornamental impenetrability as samurai castles, like those at Himeji and Matsumoto, with their pretty peaked roofs and escarpmentlike walls. The centerpiece of almost any suit of armor is the helmet, and the large selection of these in Boston gives a vivid sense of their imaginative possibilities. Some examples are fairly plain. The oldest here, from the Kamakura period (1185-1338), is essentially an inverted iron bowl prickly with protruding rivets. A 16th-century helmet inspired by a European prototype is similarly straightforward, though images of lions and peonies, inlaid in silver and gold, give it a sun-glinting flair. Beyond this, though, we're on uncharted millinery terrain, part Easter Parade, part Halloween. There are helmets in the shapes of dragons, devils, eggplants, axes, ocean waves and rhinoceros horns. Some have face guards in the form of scary, glowering faces. The most eye-catching of all have sculptural enhancements on top. Some additions are clan or family crests cast in gilded metal: chrysanthemums, a crescent moon, a butterfly. Others are Buddhist images. One 16th-century helmet has a lacquered figure of the bodhisattva Fudo Myoo planted, like a miner's lamp, above its brim. Another, with flame-shaped flanges rising from its crown, is conceived as fiery jewel, with the symbol of the patron goddess of archers at its center. A third is capped by a single piece of upright wood, about four feet tall, painted to represent a hawk's feather. Samurai! Armor From the Ann and Gabriel Barbier-Mueller Collection" continues through Aug. 4 at the Museum of Fine Arts, 465 Huntington Avenue, Boston.