In their splendid 1200-page book (no kidding!) on ethics and the law for the health professions, Professor Ian Kerridge, a Sydney haematologist and academic ethicist and colleagues, begin with a definition of ethics – ethics is deliberation about what we ought to do.

And that ought takes a thousand pages to determine; as what it means it is not always, or even often, easy to understand.

Ethics penetrates just about everything that doctors do.

Take the matter of tobacco companies now seeking to diversify into health technology.