knowledge. Observation, however, is highly subjective. Wittkin, in his book Personality Through Perception demonstrates that what people observe actually provides more information on their personality than i t does on the objects they are observing. Observation is, in fact, the work of the brain. I t involves formulating a hypothesis to interpret a particular pattern of lines and shadows detected by the eyes, and different people are likely to formulate different hypotheses, and will thus see different things.

I n addition we are still assuming that the correlations observed in laboratories constitute bona fide cause and effect relationships. Thus we observe the presence of a pollutant and a particular biological effect and assume that the former causes the latter, but i t could, conceivably, be the other way round. Or both could be the result of a third factor, or a variety of other factors, or, what is most likely, the relationship between the two, may be of a feedback nature: both may be affecting each other or may be in mutual interaction with other factors. An example points to the naivete of crude emperical correlations: Imagine an employee of a large company cherishing the desire to become its chairman. He might make the astute observation that chairmen of large companies owned Rolls Royces from which he could infer quite justifiably (if naive correlation is regarded as a valid means of obtaining knowledge) that all he had to do was to buy a Rolls Royce and his most cherished dream would be realised.

Empirical correlations cannot, by themselves, constitute evidence, and i t is about time our experts realised this. A Scientific proposition must be based on a model. Its value, or the extent to which it constitutes evidence, must depend on the capacity of this model to represent the world. This it can never do perfectly since the number of factors influencing any given situation in the world are infinite, whereas models, re­

gardless of the informational medium used, can only take into account a very limited number of factors.

I t is only by basing our behaviour on the best available model, regardless of its deficiencies, that we can maximise our chances of survival and such a model, I am sure, would favour Professor Bryce Smith's thesis rather than that of the experts.

Four thousand people died from the London smog of 1952 before the Clean Ai r Act was passed. What sort of disasters are required to provide us with the "evidence" that current pollution levels are getting out of control? Highly trained scientists are not needed to count the corpses and measure the pollution levels in their vital organs. Yet the fact that they are not at the moment being called upon to perform such tasks is the only grounds they have for stating that present pollution levels are acceptable. Indeed all that is implied by such statements is—so far, so good.

How to prevent erosion... .. . of your income by taxation, and of your capital by estate duty. Estate conservation and income supplementation are of vital concern to those of all ages who wish to bequeath capital. Yet in many cases i t is possible not only to increase substantially the net value of an estate passing to heirs but, at the same time, to make a material improvement to the estate owner's net income.

As members of a large international insurance broking group, we offer specialist advice and service on all insurance matters—including investment schemes to appreciate capital and the provision of maximum mortgages.

Stewart Smith (L. P. & M.) Ltd.

life, pensions and mortgage consultants Aldwych House, London WC2B 4HH TELEPHONE 01-242 0651

AN D A T BRISTOL, CRAWLEY, LEICESTER, LIVERPOOL, MANCHESTER, GLASGOW, EDINBURGH & ABERDEEN

4 A hundred years ago, Herman Melville asked "whether Leviathan can long endure so wide a chase, and so remorseless a havoc?" Today, in more prosaic words, the question remains: What would be lost i f whales were gone from the sea? Of what possible use are whales to men ? Aesthetics aside, who cares i f the whale goes the way of the dinosaur?

Can Leviathan long endure so wide a chase ?

by Scott McVay