I am driven to my wits' end by my fellow humans' feeble grasp of principled reasoning. Take this week's announcement of new government proposals. Anyone caught with drawings (or computer-generated images) of child sexual abuse will face up to three years in prison. This will close what ministers are now calling a “loophole”.

That was not yesterday's argument. When the existing ban on photographic images was enacted, the argument in principle was that real children are exploited and harmed to make these images, which is true. That entire philosophical plank on which the legislation

rested has now been kicked casually away. If you, alone in your room, put pencil to paper and draw - for your eyes only - an obscene doodle involving a child, you will invite a prison term of up to three years. There is real scope for vindictive citizens to ransack desks or bins and call the police.

Maria Eagle, the Justice Minister, said that the move was not intended to curb creativity or freedom of expression but to tackle images that had “no place in society”. Crikey - the intellectual sloppiness! The move does curb creativity and freedom of expression: it curbs both in pursuit of what its proponents consider the greater public good. No censorship in history has ever been advanced on any other ground.

And it establishes a principle: that images with “no place in society” should not be allowed to exist. So what about racist, or sexist, or sadomasochistic, or gratuitously violent, or homophobic, or anti-Islamic, or anti-Christian images produced not for publication but for private gratification? The logical extension of Ms Eagle's principle is almost boundless.

Even as I write I realise the lament will be a lonely one. Some will even think I have a soft spot for child-molesting. I know I am wasting my time.

But, hell, I'll stick to my guns. Another example of careless jurisprudence this week: on Monday a new law came into force requiring fortune-tellers, clairvoyants, astrologers and mediums to stipulate explicitly that their services are for “entertainment only”.

Well, trades descriptions legislation is anciently established; but in the realms of the spirit, prophecy, invisible worlds, ghosts and human souls, it has generally been felt that the whole thing is too cloudy for law. By bringing access to other spiritual dimensions into line with access to (say) a British Airways club class lounge, and by deeming in law - for that is what this measure does - that claims about worlds undreamt of in your philosophy, Horatio, are false, Parliament has taken a serious step in principle, even if the measure itself is trivial and most clairvoyants are only jokers anyway.

What, for instance, about the “faith” community? Perhaps it's there in the legislative small print already. There will have to be an exception in law for “religions”. Whereupon clairvoyants will presumably rename themselves spiritualists. And spiritualists will presumably claim the status of a religion. Whereupon lawmakers will stipulate that a “religion” has to centre around a deity. Whereupon Buddhism will cease to be a “religion”; and...

...Well you see the philosophical marsh into which this new principle leads. Is Parliament aware of any harder evidence for the efficacy of faith-healing than for the reliability of clairvoyance? I'd like to hear it. Otherwise, let the collecting boxes in church display a sign “for entertainment purposes only” and let Catholics buy candles to light “for entertainment purposes only”; and let trips to Lourdes be sold “for entertainment purposes only”. And let the raiment of the priest administering the Sacrament be embroidered likewise.

Imagine the churchyard billboard: the Power of Prayer (for entertainment purposes only).

I am occasionally reminded what a troubling spectacle I may present. On Saturday in Derbyshire I flagged down a car heading for the holiday cottage near our house, and said: “Park at the end; your friends have already arrived.” Seized with a conviction (erroneous) that I recognised this elderly couple, I gushed: “Haven't I seen you somewhere before?” They said nothing, rolled up their window and pulled away rather fast. Odd.

But think it through, Parris. I was tacking old carpet on to a tin roof so honeysuckle will spread over it. I was shoeless and unshaven. There was a cut on my forehead. My favourite old shirt's collar was frayed to ribbons. My principal fly-button had gone.

In my right hand was a Stanley knife, in my left a hammer and a reel of fishing line. From my top pocket the sharp end of an awl stuck out. Poor dears. They must have thought they'd driven into a scene from Deliverance.

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