Abstract
This paper will begin with some very broad and general considerations about the kind of biological entities we are. This exercise is motivated by the belief that the view of what we—multicellular eukaryotic organisms—are that is widely assumed by biologists, medical scientists and the general public, is an extremely limited one. It cannot be assumed a priori that a more sophisticated view will make a major difference to the science or practice of medicine, and there are areas of medicine to which it is probably largely irrelevant. However, in this case there are important implications for medicine, or so I shall argue. In particular, it enables us to appreciate fully the potential medical significance of some of the most exciting contemporary advances in general biology, in such fields as epigenetics, metagenomics, and systems biology; and part of this significance is that these advances have raised serious doubts about how we should understand the biological individuals that medicine is generally assumed to aim to treat