Finally, he continued, 'What would you say if I told you that I had found a way to tap into a man's essence?'

I said nothing, for he obviously meant this question to be rhetorical, but I was worried by the turn it was taking. Many times in the past, we had disagreed - quite violently at times - over Jekyll's theories of the human body and the human mind.

'I believe I have found a way - a physical way, mark you - to reveal the essence of a man. I believe I can strip away the outer layers and reveal the source of a man's humanity.'

This was exactly the kind of talk that I deplored, and I shifted uncomfortably in my seat. 'That's all very well, Henry, and I don't doubt that if you say that you can do this thing, then you can. But, just because you can do a thing does not mean to say that you should. We've spoken on this topic many times, and you know my feelings. You should not dabble in the way we have been made. To do such a thing is an affront to the Lord and can only result in tragedy.'

'Nonsense!' he snorted. 'If God did not want us to learn and grow then He would not have given us enquiring minds and free will. Just as we are made in His image, why should we not seek in turn to create life, but improved?'