"Google. Facebook. Twitter. Repeat. We live in a world unimaginable even a few decades ago, one like no other in human history. It's a parallel world where we can be on the move in the real world, yet always hooked into an alternative time and place. And although it's a two-dimensional world of sight and sound, it offers instant information, connected identities, and constant novelty. In this world, our screen technologies are increasingly where we work, where we unwind, where we relieve our boredom and where we learn. The subsequent transformation in how we live and think is a vitally important issue, perhaps even the most important issue of our time. When toddlers are given iPads, and adults spend ten hours a day staring at a screen, can we afford to assume that our brave new screen technologies are harmless tools? Blending a wide range of scientific studies, news events, and cultural criticism with brio and verve, Mind Change presents an incisive snapshot of the global 'now.' Greenfield examines how the dawn of the Digital Age has already altered our cultural landscape, fueled an epidemic of oversharing, and transformed how we learn, remember and spread information -- and how these innovations are changing our physical brains. A warning cry, a shot across the bow, and a call to action, Mind Change explores the social, cultural and physiological ramifications of our new digital lifestyle"--

Historically, there has been great deliberation about the limits of human knowledge. Isaac Newton, recognizing his own shortcomings, once described himself as “a boy standing on the seashore . . . whilst the great ocean of truth lay all underscored before me.” In Ignorance, Nicholas Rescher presents a broad-ranging study that examines the manifestations, consequences, and occasional benefits of ignorance in areas of philosophy, scientific endeavor, and ordinary life. Citing philosophers, theologians, and scientists from Socrates to Steven Hawking, Rescher seeks to uncover the factors that hinder our cognition. Rescher categorizes ignorance as ontologically grounded (rooted in acts of nature-erasure, chaos, and chance-that prevent fact determination), or epistemically grounded (the inadequacy of our information-securing resources). He then defines the basis of ignorance: inaccessible data; statistical fogs; secreted information; past data that have left no trace; future discoveries; future contingencies; vagrant predicates; and superior intelligences. Such impediments set limits to inquiry and mean that while we can always extend our existing knowledge-variability here is infinite-there are things that we will never know. Cognitive finitude also hinders our ability to assimilate more than a certain number of facts. We may acquire additional information, but lack the facility to interpret it. More information does not always increase knowledge; it may point us further down the path toward an erroneous conclusion. In light of these deficiencies, Rescher looks to the role of computers in solving problems and expanding our knowledge base, but finds limits to their reasoning capacity. As Rescher's comprehensive study concludes, ignorance itself is a fertile topic for knowledge, and recognizing the boundaries of our comprehension is where wisdom begins.