Sally Gross wrote:
I find myself wondering whether we, in these decadent times, no longer breathe so that it becomes impracticable to be mindful of breathing...
This isn't really the method. Mindfulness is a mistranslation of sati. Introversion of attention. They way Satipatthana is taught is a bit screwed up. When there is an urge, there is a change in the body, like heart rate or respiration. A feeling comes about, like tension. A mood arises, like anger. And thoughts arise. When one pays attention to these things happening, they slowly come to a stop, leaving no e-motion other than breathing, then one enters into jhanas. In the fourth jhana one begins to see the skandhas working. It's like being sucked down a drain. It all happens automatically. Thus, taking mindfulness of feelings, etc., is dividing up what is a whole, and so it becomes much more difficult to get the result.