Howard Jacobson: We don't need scientists to point out the obvious: men are enslaved by gadgets

"There's a bit of testicle," I heard someone say on Melvyn Bragg's In Our Time last week, "at the bottom of our most sublime feelings." The quotation was from Denis Diderot, philosopher, critic, encyclopaedist, discreet pornographer. If I could leave this week's column at that, I would. Reader, there's a bit of testicle at the bottom of most things. Now good day to you.

But brevity is no virtue when they pay you by the word. And besides, there is a little teasing-out still to do. Not of Diderot's meaning, which is clear enough, but of its applicability in a world inimical to the testicle. Forget the sex war: it is not from women that the testicle has anything to fear - for our part we have nothing but contempt for the sort of men who pester every woman they meet then call them ball-breakers the minute they are repulsed - but from science. I will speak figuratively in due course, but for the moment I mean that literally. Technology spells the end of our virility.

Barely a day passed last week without the publication of a report warning of the dangers posed to men and their fertility by the artificial way we live. Take, for example, the mobile phone. Use a mobile phone and your sperm's not worth counting. That's the finding of the Reproductive Research Centre at the Cleveland Clinic Foundation. Be on your phone four hours a day and your sperm is down to 50 million per millilitre, which might sound a lot but rest assured it isn't. Be on your phone even longer and you could fall as low as 20 million per millilitre.

Scientists sceptical of these findings argue that the longer you are on the mobile phone, the better it should be for your testes, given that the phone is spending more time up around your head and less time heating up your trouser pocket, but that supposes there is no link between the head and the testes - a supposition which, after Diderot, it would be unwise to make. For ourselves, we accept the research without reserve. Anyone who uses a mobile phone for long periods knows the sensation of something draining away from him. In our experience, even listening to other people speaking on their mobile phones can make you infertile.

We do not, in this column, express grief we do not feel. There are things to be said for lower sperm counts. It's more than a hundred years since the child of Jude the Obscure hung himself and his siblings from clothes hooks, having heard his parents say it had been better they had not been born. "Done because we are too menny," the suicide note says. If a mobile phone can avert such a tragedy today, generally make the world a less populous and miserable place, who are we to stand in its way? Nor do we hold with the promiscuous sperm-throwing of many men of our acquaintance. Of all the ways to be a man, filling the world with little simulacra of yourself is the least manly. One child should be enough for any of us.

But, as the Cleveland project makes clear, sperm count isn't the only measure of the harm being done. "On all four parameters - sperm count, motility, viability and morphology", there are significant differences in the all round sperm-healthfulness of those who are never on the phone and those who are never off it. And while 20 million per millilitre might not worry you unduly, particularly if you are already the father of legions, the thought of your sperm lacking motility - that's to say becoming incapable of free, spontaneous and independent movement - surely will. What man wants to think of his sperm as a stagnant pool rotting in his testes?

So what, short of throwing away our mobiles - a measure too drastic to contemplate - are we to do? Make a fight of it, write a letter to the mobile phone manufacturers? Be careful not to do so on your laptop, because the laptop, too, is beginning to cause concern. Why? Because it heats up our laps. Wherever there is the heat of technology, reader, there is damage to our reproductive and erogenic self-esteem.

It is so depressing you might think a selective serotonin re-uptake inhibitor, otherwise known as an antidepressant, is called for. Big mistake. Researchers from Cornell claim they have evidence that such drugs can reduce your sperm count so drastically that you will remember your 20 million per millilitre days as paradisally amplitudinous. Close to zero is what we're talking now. And that's before we address the issue of ejaculation, which on this occasion - beyond noting that here, too, happy-science reduces our effectiveness - we won't.

Scientific and technological advance unmans us, that's where I stand. And in truth we hardly need more scientists beavering away in Cleveland and Cornell to tell us so. Let a phone ring in a crowded room and every man loses his independence of will. He must answer it. Why? What is the compulsion? Women are far more insouciant around a ring tone. Perhaps it is because they are used to being chased from an early age and have trained themselves in the arts of evasion and refusal, knowing how to ignore an imploring phone being one of them. But when a phone rings for a man he thinks it might be someone saying yes at last. Yes, you can have the job; yes, you have won the Nobel Prize; yes, you can come round to my apartment even though you lack the motility of sperm to be effective when you get here.

It is in man's nature to be slavish, but the gadgetry of our times extends the number of his masters.

Good, I thought, when I read that a Norwegian hacker had upset the hegemony of the fatuous iPod. But apparently it's bad, not good, because the upsetting of the hegemony means - I have no idea how - the availability of more and cheaper tunes for everybody. Will someone tell me why we need more tunes? Is this not already a tune-ravaged planet?

But it is not the music itself that will kill us, but the means we come by it. No better than machines, we plug ourselves in each day to receive our functioning instructions from an intangible, disembodied source on which our sperm, trashed and humiliated by the microchip, has neither influence nor effect. I know what some of you are thinking: that there is testicle at the bottom of my reasoning. I make no apology. We must cling to what little testicle is left.