The Son of The Master was a story that was going to be inevitable as soon as I introduced Marton as a character in the story ‘Nurture Versus Nature’. In that story, The Doctor was adamant that nurture counted for everything in the development of a personality and would not have it that Marton had an evil bone in his body.

And that is something which I think is largely true. Children are not inherently evil or inherently good. Most children, for that matter, are not simply one or the other. They are little angels with a certain amount of devil in them, and that’s what they ought to be. Children from council estates who grow up to be car thieves and drug addicts like their parents do so not because of genes, but because of their environment and their no-win situation.

But then, a few weeks before this story went online, I saw John Barrowman’s one off programme, The Making of Me, in which he set out to prove that he is gay because of his genes. And I do think he is right. So a whole new kettle of fish is boiled here. If there is a ‘gay gene’, is there an ‘evil gene’?

If that is so, then this story does contradict my own beliefs. Because I don’t believe somebody who is born gay can simply go against that nature and live ‘straight’. The example put forward in Barrowman’s programme of a man who had chosen to get married, have children, was, I think, a man under a self-delusion who will eventually realise that he is living against his nature in order to conform to other people’s demands on him.

So by the same token, Marton, who is not simply the son of The Master, but actually is a clone of him, with his exact DNA – as indicated in the previous story, Exiles on SangC’lune by the pyramid growing where The Master’s pyramid was. So if it is just nature, Marton, by trying to live as an honest man, is denying his true nature much as the gay man going straight was.

Yes, but only if we accept that The Master, himself, was evil because he was born that way. And, in fact, the very little we know about The Master’s background suggests that he wasn’t. In the classic series, The Doctor talked occasionally about The Master as a school friend, ambitious as he was, rebellious, as he was, but not driven by any particularly negative force. In the ‘New Who’ the Tenth Doctor described how The Master’s mind was skewed by his experience with the Untempered Schism when he was very young, and in the two episodes involving The Master, The Doctor tried very hard to persuade The Master to give up his evil ways and make amends. He wouldn’t have done so if he believed The Master couldn’t be saved. The Doctor does think that The Master became evil because of his environment.

Interestingly, The Doctor’s other nemesis, Davros, is also presented as somebody for whom environment, upbringing, caused his madness and lack of ordinary morality. The audio adventures, I, Davros, make for interesting reading with the nature/nurture argument in mind. He, too, seems to have started out as a basically all right kid. He cared about nature and was upset about the poisoning of the environment because of the war with the Thals, especially the destruction of the lake near his home – which turns up in the TV stories full of mutants, of course. A series of events slowly turn him to the dark side.

Come to that, look at some other classic science fiction baddies. Darth Vader is another example. He started out as a good guy, but circumstances turned him to the dark side. In the Batman films, his arch enemies have some kind of turning point in their backgrounds where they became evil. The same is true of Spiderman. I’m not too sure about Lex Luthor, Superman’s nemesis. He seems to have been a bad egg all along, but perhaps he’s the exception to the rule.

Anyway, the point is that in science fiction at least, evil does seem to be something that is accumulated through unfortunate circumstances rather than genetic. Marton, therefore, with The Master’s genes, doesn’t have to follow in his footsteps. He has had a stable home with loving parents and his ambition and drive can be channelled into positive goals. His occasional flashes of aggression and hot headedness don’t have to be self-destructive. They do need controlling, of course. The Doctor was obviously alarmed at the way Marton used his mental powers against the Follower of The Master. But the boy had no desire to kill, only to protect the people he loves.

Is the jury still out on the debate? Yes. It is bound to be. Because genetics aside, people are always going to be unpredictable and unique.

Meanwhile, The Doctor and Marton have had their DNA rewritten to make them Human. And just what does THAT say about the issue? If DNA can be manipulated so easily, who knows? What it does mean is that Rose gets to spend a couple of nights with a man who looks like her husband, sounds like him, but in some fundamental ways, isn’t him. As for what happens to John Smith and son when the Followers of The Master catch up with him – watch this space.