  This picture of explaining cancer might be expected to resonate quite well with the picture of scientific explanation advocated by what has been called the “new mechanists.” According to this view, one of the central aims of biological scientists is the identification of mechanisms. The biological sciences, on this view, are unique in their focus on mechanisms, rather than laws or general principles, of the sort (typically imagined) to be central to the physical sciences. A mechanistic explanation identifies parts and processes that typically yield specific outcomes of interest (Machamer, et al. 2000). If we wish to understand regulation of apoptosis (cell death), for instance, we might identify particular genes and proteins that play an important role in cell senescence, and determine how their activity and organization yield (or fail to yield) a given outcome. This mechanistic picture of the aims and character of explanation in the biological sciences seems prima facie to characterize current cancer research quite well, or at least the past 25 years of this research.