THEY STAND MUTE, the Europeans who lived 37,000 to 10,000 years ago during the last great glacial age. Yet out of the layers of dust and time have come engravings and paintings that speak of acute observation, master craftsmanship, and, to author Alexander Marshack, a Research Associate of Harvard University’s Peabody Museum, something even more—clues to the human motives behind the art.

What did the artisan have in mind, he who set flint point to reindeer antler  about 12,000 years ago? Various theories have explained this kind of art as hunting magic, or as sexual symbolism, or as ancestor totems. Not satisfied with these concepts, the author began his analysis by taking a closer look at Ice Age artifacts than had ever been attempted before.

This 14′/2-inch baton de commandement, an engraved staff that may have been used in ritual and perhaps served also as a spear straightener, had been known for nearly a century. Yet under a microscope Marshack saw details previously overlooked or inaccurately reported. His tracings here show all its images as if unrolled, and color coded for clarity.

If the bull and cow seals (brown) and the male snakes (red) were self-evident, the upside­down fish (orange) was not. The microscope revealed that it was not a common mackerel, as it had previously been called, but a male salmon with the jaw hook distinctive of the annual spawning migration upstream—a time when seals follow to feast on the fish.

Three graceful forms (dark green) resemble plants, not harpoons for hunting magic. A sprout (lavender), a flower (green), and three small many-legged water creatures (deep purple) round out a visual treatise on seasonal ecology. And, the author feels, a schematic crossed-out ibex head (tan), and perhaps another beside it (dark blue), may be symbols that stand for the whole composition and for the idea behind it—the coming of spring, marked by sacrificial killings.

Not all the author’s colleagues agree with the conclusions set forth in his startling book, The Roots of Civilization, or in this article, which outlines his most recent research, aided by a National Geographic Society grant. Yet most concede that his techniques—microscopic examination and infrared and ultraviolet photography—point the way to profound new insights into the life and cultural development of Ice Age man.

If, as Alexander Marshack has come to believe, man of that dim, often frigid past thought essentially as we think, what he crafted helps to chart the ultimate labyrinth—the complex, subtle, and ever-changing territory of the modern human mind.