Neuroscientists have discovered primitive “bottom-up mechanisms” in our brains that, as the authors of a 2004 article in Current Biology put it, “operate on raw sensory input, rapidly and involuntarily shifting attention to salient visual features of potential importance.”” Our predisposition is to shift our gaze, and hence our attention, from one object to another, to be aware of as much of what’s going on around us as possible. “The natural state of the human brain, like that of the brains of most of our relatives in the animal kingdom, is one of distractedness. “Often, when we came to see him, we found him reading like this in silence, for he never read aloud.” Baffled by such peculiar behavior, Augustine wondered whether Ambrose “needed to spare his voice, which quite easily became hoarse.”” “When he read, his eyes scanned the page and his heart explored the meaning, but his voice was silent and his tongue was still,” wrote Augustine. In a famous passage in his Confessions, Saint Augustine described the surprise he felt when, around the year AD 380, he saw Ambrose, the bishop of Milan, reading silently to himself. The new codices, like the tablets and scrolls that preceded them, were almost always read aloud, whether the reader was in a group or alone.

Silent reading was largely unknown in the ancient world. “Even as the technology of the book sped ahead, the legacy of the oral world continued to shape the way words on pages were written and read. “Should the Egyptians learn to write, Thamus goes on, “it will implant forgetfulness in their souls: they will cease to exercise memory because they rely on that which is written, calling things to remembrance no longer from within themselves, but by means of external marks.”” We become, neurologically, what we think.” “Descartes may have been wrong about dualism, but he appears to have been correct in believing that our thoughts can exert a physical influence on, or at least cause a physical reaction in, our brains.

Carr the shallows