It is striking just how similar Descartes' theory on 'reflex' is to Pavlov's theory of 'conditioning'. Just as in Pavlov's conditioning experiment, performed two hundred and seventy one years after Descartes' letter outlines his theory of 'reflex', the two stimuli necessary for conditioning, the conditioned and unconditioned stimuli, are paired causing the 'planned conditional response'.

One thing is for sure - saying thank you is a nice thing to do. It makes you feel good, and makes the receiver feel valued. We may not subscribe to the hand written parchments of old, with ruler straight lines and wafty words of gratitude penned from inky quills, but we do still subscribe to basics of liking to give and liking to be thanked.

When I imagine my own kids one day going through my "box" of memories I realise that there is no box. Even my inbox they won't have access to. Emails have replaced letters, pictures on facebook have replaced photographs, iTunes downloads have replaced CDs which in turn have replaced tapes and records - and then there's the Kindle.

A bit of background This emotional journey will revisit the stories of my Uncle Joe once again. I hope you will enjoy them, and think of your family a...

A bit of background This emotional journey will revisit the stories of my Uncle Joe once again. I hope you will enjoy them, and think of your family ...

A bit of background This emotional journey will take in the stories of my Uncle Joe. I hope you will enjoy reading his letters (the original versions...

An alarming majority of people now eschew sending written thanks to their nearest and dearest who have spent their hard earned money on presents. Some will half-heartedly try to express their thanks by sending a thank you text or email. I can't imagine doing such a thing. I am coming out in hives as I write. That said, I suppose they are better than nothing.