Presents an examination of historic preservation's underlying philosophy. The fields of art and science are often entwined in historic preservation; architecture, employing both art and science, has been a major influence, and the sciences of chemistry and physics have proved invaluable in restoration and conservation. However, the author detects a shift in influence of historic preservation away from its roots in the humanities and arts and towards the sciences. The article concludes that such a trend has important implications for the future orientation of historic preservation thought and practice.