THOUGHT is dangerous, especially in a game like golf when a stray item rattling around the brainbox can surface uncannily at the precise moment of execution of a crucial four-foot sidehiller or a delicate floater over a bunker.

Suddenly remembering that until now you've forgotten this is your wife's birthday is a certain recipe for missing the putt by a foot or stubbing the ball into sand. The unwelcome intrusion of a negative ''I'm going to miss,'' will have the same result.

Once the thought has been, well, thought, there is no way you can unthink it although partial success can be achieved by the use of reverse psychology which tries to develop the negative thought in a positive way.

In these instances secondary thoughts like: ''Okay, if I'm going to miss I've nothing to lose by giving it a try,'' or ''it's nothing a bunch of flowers won't fix provided I don't stay too long at the bar and I'll get there sooner if I hole this putt,'' might produce the desired result.

''Swing thought'' has for long been a term in the golfer's lexicon. It might be a shape like a wide arc or a high follow-through or it might be anatomical such as an awareness of the pressure exerted by the left pinkie on the clubshaft or an inward flex of the right knee on takeaway. By far the most intriguing is the ''think of nothing'' thought.

This method, though, is difficult to apply. After all, if you consciously think of nothing you are actually thinking of something and that something is nothing. So you must learn to empty your mind, a state which irritatingly seems easier to achieve in situations away from the golf course where you need to be mentally alert such as driving a car.

If by now you are confused then brace yourself for the mental meanderings of Padraig Harrington, who has a suitably Irish approach to the subject.

Asked about his swing thoughts in the current edition of Golf World he replies: ''I have about 20 at the moment. There's far too much going on. The other day I was trying to pause at the top of the backswing so that I didn't 'hit from the top'. It didn't work. In fact it made it worse.

''The swing thought after that was to try not to have any swing thoughts which proved quite effective. Blanking everything out and just focusing on the target is a good idea.

''Some people would say that because you've got a positive image of what you're trying to do, then that's why you do it.

''But I actually think that it's because you have no image of what you don't want to do, that you end up doing what you want to do.''

If you don't believe negative thoughts can produce negative results then try an exercise or two, preferably on someone else. In a bounce game with a pound at stake, try to plant doubt in an opponent's mind by drawing hazards to attention in a casual and subtly negative way.

''It's a long time since I've seen anyone out of bounds on the right here,'' is a good one, and so is: ''With your fade, that bunker shouldn't come into play.'' On the tee of a par-3 you might try: ''It looks like two clubs more than you think, and on the green: ''Your putt is so fast it must be impossible to leave it short.''

Now stand back and watch what happens.

Don't try this in formal competition though or an extremely negative result might ensue when you are reported to the committee?

In the seriously competitive environment you are left to your own inner demons. Some experts talk about remembering good shots by storing them behind doors. Then when you are faced with a similar shot you merely search through your mind for the right door and open it. Personally I don't like that idea. What if you open the wrong door and release a real monster. Cite Doug Sanders' missed little putt that cost him the 1970 Open at St Andrews. But that's being negative again.

It's better to take Harrington's advice and not think at all. How, though, do you achieve this?

My favourite exposition on the topic is in Leslie Nielsen's Stupid Little Golf Book, a merciless send-up of golf coach Harvey Penick's Little Red Book.

With absolute clarity Nielson advises: ''You must never forget not to think. But you can't just forget not to think - you must remember not to remember to think, and you must not remember that you forgot to think.''

On the planting a thought theory he is equally positive: ''Even if you sometimes forget not to forget not to think about your swing, you can certainly see to it that your opponent remembers to remember to think about his.''

Nothing to it, really.