Mario Livio's book The Golden Ratio: The Story of Phi, the World's Most Astonishing Number (2002) chronicles the history, not of a person, thing, or concept, but a number. However, this number or notion of proportionality or the 'Golden Ratio' has been invested with such cultural, emotional, and religious importance it has taken on a character in and of itself. Philosophers and poets have used the idea of proportional perfection in the universe to justify the aesthetic behind their works and also to prove the existence of God. Deny the Golden Ratio, and deny the idea that aesthetics or religious principles exist independently of human craft and culture.
             Phi has fascinated mathematicians for centuries, but it is less famous than its similarly named cousin Pi, which and even inspired a holiday (3.14, March 14th or 'Pi' day). So what exactly is Phi? Although 3.14 may be more famous, phi may be, according to Livio, "even more fascinating," and have a more notable impact on our daily lives, in the ways that it relates to our culturally ideas of proportion and goodness. Livio does not believe that the assumption that proportionality equals beauty and quality is inherent in nature, rather he believes it is a long-standing cultural construction. Still, he spends much of his text presenting the case that this ideal of universal proportionality might be true, with examples drawn from the ancients to the present day. Because it is so important in our culture, it must be debated.
             Phi is a number, common in both art and the natural world. Its advocates say that the intrinsic and innate love of proportionality within the human brain is rooted in the exterior universe. The Parthenon in Greece, crosses in graveyards, the ratio of the height of the navel to a woman's total height, sunflowers, Salvador Dali's paintings of rose petals, mollusks and Leonardo da Vinci's "Mona Lisa" all exhibit this ra...