Abstract
Cancer is a puzzling and frightening disease or set of diseases. Cancers have afflicted multicellular living beings for more than 200 million years, and there is evidence of cancers among ancestors of modern humans going back well over a million years. Unlike infectious diseases, parasites, and many environmental diseases, cancer is not primarily caused by some entity that is foreign to our bodies. Its agents of destruction are human cells that have, as it were, slipped their reins, and have been recruited and to some extent transformed into pathological organisms or the building blocks of tumors. As Anya Plutynski puts it in Explaining Cancer : "Cancer may be viewed as akin to a car breaking down, a process...