Dependent Origination is the teaching (that life) is not the mere play of blind chance, but has an existence that is dependent upon conditions. That, precisely with the removal of these conditions, those things that have arisen in dependence upon them-thus also all suffering-must perforce disappear and cease to be.
From the scientific view, the theory of karma may be a metaphysical assumption -- but it is no more so than the assumption that all of life is material and originated out of pure chance
We manage to swallow flesh only because we do not think of the cruel and sinful thing that we do. There are many crimes which are the creation of man himself, the wrongfulness of which is put down to their divergence from habit, custom, or tradition. But cruelty is not of these. It is a fundamental sin, and admits of no argument or nice distinctions. If only we do not allow our heart to grow callous, its protest against cruelty is always clearly heard; and yet we go on perpetrating cruelties easily, merrily, all of us - in fact, anyone who does not join in is dubbed a crank.