From time to time, I toil mentally putting together Grand Theories. I have several, many merely the nucleus of an idea. One, however, recently came to fruition while I was re-reading the collected works of Darby Conley, the author of the "Get Fuzzy" cartoon strip. It just might rock your world, baby. Here we go.

You know how there are "dog people" and "cat people"? The terms are used to denote those who love one of the species, often disliking the other one. I am a "cat person", in that I find cats to be excellent creatures, independently minded and able to look after themselves. The dog, on the other hand, is rarely more than a dependant.

Dog people argue that dogs offer unconditional love. You may have heard the propaganda to the effect that a dog is man's best friend. This is a canard, which in other circles is what they call a duck, but let's get beyond that. There are no "duck people".

Of course a dog loves you. You feed it. Without you, a dog has no meaning. Nine thousand years of servitude to the master, and the mutts have forgotten the fine art of foraging and, indeed, survival. (I hear a bank of editors screaming: "What does this have to do with finance? Who else do we have that can write columns?" Hold your horses, which are even dumber than dogs, by the way.)

What we've established so far is that a dog is as dumb and subservient as a sentient being can be, except for horses and ducks. The cat, meanwhile, copes for itself. No wonder the Egyptians worshipped them. The Egyptians, by the way, didn't just invent a way of walking, they built the pyramids, worshipped cats, and swanned around singing "Egypt is Another World", probably.

Cats are better than people, in many ways. They didn't until comparatively recently in their development have vets, cat dentists, cat food in tins, or any of that jive, and yet they did well enough to be worshipped by humans. Pretty good going, I'd say.

Well, all of that you knew. A Grand Theory must be built on solid foundations, and I believe we have QED'd that right about now.

Another old saw has it that there are two kinds of people in this world: those who say there are two kinds of people in this world, and those who don't. That's what we in the finance business call humour. There are definitely two kinds of people in the world of finance: those who are predominantly savers and those who are essentially spenders. The savers write the newspaper columns and the spenders phone them up and scream abuse at them.

Here you might want to hold onto something. For, like a train rattling through a junction, we now approach the points. Cats are spenders. If you've ever laid out a week's meals for a cat while you slid off to New York City for some shameful behaviour, only to return home an hour later when the flight was cancelled, you'd know that. You would have discovered that the cat, with no thought for the morrow, had eaten the entire week's rations and then thrown up in your $500 dress shoes.

Dogs, however, are savers. Wrong, you say, a dog will guzzle down its food as fast as is doggily possible. That's true, but once full, the hound will slope off and enjoy an 18-hour nap, often leaving food behind. Plus, and here comes the inescapable proof, dogs bury bones. In their tiny doggie brains, they somehow understand that a bone earned is a bone saved.

Of course, being as dumb as they are, they quickly forget where they buried the bones and are then forced to spend hours standing near humans who are eating, in case any food should drop to the floor.

That, you might think, is quite as grand a theory as ever you heard. You'd be right, but there is more. A Grand Corollary, if you will, and here we enter into Nobel Prize territory. Get this. Human savers tend to prefer cats, Nature's spenders. Human spenders, on the other hand, can't get enough of dogs.

Why? Is it possible that deep within human savers lies the spending gene, repressed so deep in the psyche that it can only derive satisfaction from watching the spending follies of others? And vice, as they say, versa. Human spenders live lives suffused with guilt and so derive vicarious righteousness from keeping a dog in servitude, as a sort of cosmic equalisation programme.

The human/dog relationship, by the way, can be summed up as "I may; you mustn't", which, come to think of it, means my Mum was a spender. Well, she would have been, wouldn't she? After all, women tend to do better in the spending department, fetishising the process into the ghastly ritual known as shopping. (Feminists may address hate mail to crombie@northrock.bm.)

See how grand this theory is? It's all-encompassing. I shall now demolish what little opposition there might be to my views. Let's start with "Your colleague Martha Myron is a saver, and she's a woman". That's true, but it serves my argument well, for she is the exception that proves the rule.

"I'm a saver and I like dogs", someone will no doubt argue. Well, as we in the academic community say, who asked you? So there we have it. The sum total of human knowledge has been advanced, and you still have the rest of the weekend to get on with other things. I'm not allowed to nominate myself for the Nobel, so I'd be grateful if one or two of you would do it for me.

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The last surviving great science fiction writer of the 1940s and 1950s passed away this week, at the age of 91. Philip José Farmer was the author of the Riverworld and World of Tiers series and an enormous body of speculative fiction. His was one of the great creative and rebellious minds of his age.

Phil was a friend and an inspiration to me. In 2002, he allowed RG Magazine to publish a short story which he had written in 1955 but which had not previously been published. It was his first appearance in print for some years and sparked a renaissance in his work.

I last saw him at his home in Peoria, Ilinois last summer. He was unwell, but found the energy to greet a few of his friends. His legacy is a world of ideas, expressed in more than 80 books and a huge number of short stories, letters, commentaries and other literary contributions. His stories are entirely readable, which, for my money, is the most important quality of well-written work.