The 'scientific' way we think today owes a lot to the seventeenth-century French philosopher René Descartes.

The 'Cartesian' approach is to reduce any complex system down to its smallest individual parts - like taking a motorcycle apart and rebuilding it as a way of understanding how motorcycles work.

From the seventeenth century onwards it was felt that you could treat the world as one great machine. Nature was assumed to be operating in a mathematically precise way. By understanding its parts you would eventually understand the whole and be able to dominate it. Thus dawned the age of the specialist and the world was fragmented into many parts to be studied and exploited by different groups of people - the physicists, the engineers, the biologists, the doctors.

And this method did prove very successful, Isaac Newton, for example, studied the individual objects he saw around him - like the apple falling towards the earth - and formulated his laws of gravity and motion to account for the relationships between these objects. Newtonian mechanics saw the world as one cosmic machine - from which human beings could stand back and observe.

Other sciences pursued the same tack. Medicine treated the body as a machine built up of components, like the heart as a pump. Biology took the analysis down to the level of cells - and even genes - in the search for the fundamental building unit. The Cartesian method seemed to offer an all-triumphant way of thinking.

But in reality the Cartesian method has severe limitations - often giving answers which only work under certain conditions and sometimes leading in completely the wrong direction. The most sever attacks on it have come from one of the esoteric frontiers of human knowledge - particle physics. The study of subatomic particles has demonstrated that at the lowest level there is no such thing as a single object. Everything is part of an invisible whole - and 'particles' take on different characteristics depending on hoe you look at them. The consciousness of the scientific observer also has to be recognized as an integral part of this system. And it even seems that every constituent of the universe can be considered as linked to every other one.

But the artificial and limited nature of the Cartesian approach had been evident much earlier, to poets at least, if not to scientists. The scientists had, for example, decided that only those things which could be measured were worthy of study - shapes, numbers and movement. Peripheral considerations like colour, taste and feelings were excluded. 'Romantics' such as Blake and Wordsworth argued that distinctions between reason and emotion or between mind and body were misleading. And we have now seen that such distinctions can be incorrect.

We know that human health, for example, is dependent on the physical and emotional environment in which we live and that breakdowns within the human body are almost always due to living in an unhealthy way. And we see that the exclusion of morality from science can produce disasters; engineers and scientists have built nuclear power stations whose waste products will pollute the environment for millions of years

Beyond this many people would argue that the Cartesian ideas have produced an aggressive, analytical male dominated society. Scientific 'progress' is overvalued compared with the quality of life and if left to decide humanity's future it will lead us all over a precipice.

Challenges to conventional science are coming from many directions. From the ecologists, from the peace movement, from feminists and from concerned scientists themselves. They argue that factors which cannot be measured are not simply to be ignored. And that we are not cogs in a machine but are small wholes who in turn are part of a greater organic whole.

Seen in this way scientists are not merely neutral observers of a machine. Just as in the sub-atomic world, so in the greater world around us they intervene and shape the way we perceive the world. Research, for example, is strongly directed both by what any society considers worth investigating and by political decisions about what investigations should be financed - as in the choice between research into nuclear or solar energy.

MICRO TECHNOLOGY offers the ability to control more and more of the world around us. So now it is the time to ask whether we should want such control - and if so what form it should take. It may be that humanity is finally recognizing not just the benefits of science, but also the distorted shape it has taken and the limitations to what it can offer.