Like Stephen Hawking, I have been living with motor neurone disease (MND). Like him, I'm one of the lucky few not to have died within months of diagnosis. I'm nine years younger than him and have had the symptoms of the disease for only 10 years, compared with his 49. However for those 10 years I've "lived with the prospect of an early death" also. Unlike Professor Hawking I am not a superstar scientist. I'm simply a small-time writer, who used to be a teacher and a vicar.

'Professor Hawking surely knows better than that some notion in your head, whatever that notion might be, makes the frustrations and pains of a terminal illness somehow more bearable.' Photograph: Jim Watson/AFP/Getty Images

It seems to me that, while some things Stephen Hawking says in the interview as it's reported are unarguably true, some are also admitted hypothesis, and some are merely tendentious. One of the features of MND both for him as for me is that it affects your ability to speak and hence pares down what you say to the bare bones. (That's not of course the case when you have time to type a script.) Hence sometimes you are frustrated by your inability to nuance your ideas. And so it may be that his very categorical answers are the nub of his opinion, but not the full expression.

For example, there's something of "nothing-buttery" about his comments about death: "I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark." It's unarguably true that there's no heaven for broken down computers, as I have found to my cost when I poured fruit juice over my laptop. The brain may be nothing but a most remarkable computer, yet there's something generically different from a computer in a brain which, when it starts to malfunction as happens in MND, can begin to love Wagner's music and "enjoy life more". That, I would say, is irrational, but not uncommon. Human beings, it would appear, are something more than machines. Maybe science will one day describe what the difference is.

Hawking tells us that "the universe is governed by science". I think I understand what he means. It is certainly discoverable by science. Scientific theories that don't fit with the evidence of the universe fail. In simple terms science is governed by the universe, not the other way round. What's interesting is that this is in effect what Hawking says talking about the beauty of science. It's "beautiful when it makes simple explanations of phenomena or connections between different observations", citing the double helix and fundamental equations in physics as examples.

I find myself admiring and agreeing with much of what Professor Hawking says, but I find his ethical deduction and his quasi-religious observation sadly lacking. "So here we are. What should we do?" he is asked. The question sounds similar to ones posed to great religious teachers of the past. His answer is disappointing: "We should seek the greatest value of our action." It's certainly thought-provoking (what exactly does that mean for this or that action?) and it is a principle that is reinforced by the experience of life-threatening illness. One could say: "Don't waste your life." Yet as a rule for life, it lacks both the impact and the practicality of the great Judeo-Christian answer to that question: "Love God above yourself, and love your neighbour as yourself." Even those who are unwilling to subscribe to the first part can understand the second part and usually admit its validity.

Finally, Stephen Hawking's headlined observation about death, that an after-life "is a fairy-story for people afraid of the dark" is both sad and misinformed. Openness to the theoretical possibility of there being 11 dimensions and fundamental particles "as yet undiscovered" shows an intellectual humility strangely at odds with writing off the possibility of other dimensions of existence.

For someone "facing the prospect of an early death", with probably an unpleasant prelude, the idea of extinction holds no more fear than sleep. It really is insulting to accuse me of believing there might be life after death because I'm afraid of the dark. On the contrary, sad though I shall be to leave behind those I love, I suspect the end of life, whatever happens, will be a relief. And, like Pascal making his wager, if it is dark, I really won't mind, because, of course, there won't be a me to mind.

Strangely enough, my theory that there is a form of life after we die is not some sort of wishful thinking. It's based on evidence. If the brain is a computer, then, when I was studying where Stephen Hawking now teaches, I came on a mass of data of which the most convincing, the neatest, explanation was that death is not the end of life. It wasn't the most comfortable nor most obvious of conclusions, but the forensic case was forceful and beautiful, providing "simple explanations of phenomena or connections between different observations". The best exposition I found was by the then director of the Institute of Advanced Legal Studies in London, Professor Sir Norman Anderson, in The Evidence for the Resurrection (later republished as part of Jesus Christ: The Witness of History). My disturbing conclusion was that, if it happened once, as seemed beyond reasonable doubt, then I needed to revise my whole world view. What you see is not all you get.

One may wish to dismiss Jesus Christ, or Julius Caesar, as fairy stories, even as bunk, but, until one has examined the evidence in Anderson's forensic manner, that's a premature judgment. I suspect many do that. As for the idea that belief in an afterlife is a consolation, it is not just about heaven. Most faiths in fact have a notion of judgment, which is hardly comfortable for anyone, although it does focus the motivation not to waste one's life. Moreover in our situation Professor Hawking surely knows better than that some notion in your head, whatever that notion might be, makes the frustrations and pains of a terminal illness somehow more bearable. That's the nonsense of those who have not been there. I can't prove it of course, but on good grounds I'd stake my life on it, that beyond death will be another great adventure; but first I have to get finish this one.