<p>Why pause and study this particular painting among so many others ranged on a gallery wall? Wonder, which Descartes called the first of the passions, is at play; it couples surprise with a wish to know more, the pleasurable promise that what is novel or rare may become familiar. This is a book about the aesthetics of wonder, about wonder as it figures in our relation to the visual world and to rare or new experiences.</p><p>In three instructive instances--a pair of paintings by Cy Twombly, the famous problem of doubling the area of a square, and the history of attempts to explain rainbows--Philip Fisher examines the experience of wonder as it draws together pleasure, thinking, and the aesthetic features of thought. Through these examples he places wonder in relation to the ordinary and the everyday as well as to its opposite, fear. The remarkable story of how rainbows came to be explained, fraught with errors, half-knowledge, and incomplete understanding, suggests that certain knowledge cannot be what we expect when wonder engages us. Instead, Fisher argues, a detailed familiarity, similar to knowing our way around a building or a painting, is the ultimate meeting point for aesthetic and scientific encounters with novelty, rare experiences, and the genuinely new.</p>