Sincere thanks Frank Hamilton for your very thorough and very interesting replies to some of my ideas. This is much appreciated.

Whether we agree or disagree on some points it doesn't matter because all your points are very well considered and just as valid as mine are.

As you say "..this opens a door to discovery which is always a good thing." I think this applies to this whole thread and the many contributors that have added to this fascinating debate.

Many of the points I have raised on this thread have been ideas to throw into the pot to invite and stimulate debate rather than firm and unshiftable convictions. This is because I am still learning and benefiting from all the knowledge and opinions expressed on this thread to date.

When I started this thread I never envisaged the can of worms I had opened. This is a massive subject worthy of detailed discussion and has attracted such diverse and conflicting views that I realise that no one can have the final and definitive answer.

But it is well worth the adventure and the journey of discovery.
Bit by bit I think we are getting there!