Some Constructive Responses - the greatest pleasure in debate

In the past few days I've received some interesting and constructive responses here, civil and wise, which illustrate the way in which serious debate among people with differing views and principles can bring us closer to the truth. This doesn't necessarily mean that people have agreed with me (though in one case it does). It's the nature of the disagreement that's important - actually taking account of what has been said, responsive to it, prepared to consider it.

What a change from certain...