Biology and Man's Estimation of Himself
Peter Medawar

Twice in its history biology has seemed to threaten our amour propre and to diminish ourselves in our own estimation. I shall describe how this came about and why it was that the threat came to nothing. I shall then briefly discuss the morality of the prolongation of life, by medical engineering or other means.

It has been said that the greatest cultural shock mankind ever experienced arose out of the recognition of anthropoid apes in the first great voyages of discovery in the sixteenth and seventeenth centuries. Chimpanzees (baby chimpanzees were described as ``pygmies'') were reported from East Africa and the ``wild man of the woods'' that Linnaeus was later to name Homo sylvestris orang-outan from South-East Asia. The apparent affront they embody lies in their being caricatures of ourselves -- unmistakably similar to ourselves in various ways like an ill-nature political cartoon.

Yet no shock was experienced. If the man-like apes had caused a deep soul searching or revaluation of ourselves, there would have been evidence of it in contemporary literature just as in Ibsen and Shaw there is a frightened awareness of the newer knowledge of heredity. Shakespeare, like Aristotle, probably never saw an ape (Aristotle refers to ``the Barbary ape'' --- but this is merely a macaque monkey). Shakespeare used ``monkeys'' and ``apes'' interchangably. For Shakespeaere, apes are nothing worse than mischievous and unduly garrulous. Pascal has no thoughts on them. The only remark of Bacon's known to me is very characteristic of this witty and reverent man: ``As it addeth deformity to an ape to be so like a man so the similitude of superstition to religion makes it the more deformed.''

Why did the apes cause so little stir? The reason, I believe, is that their existence was half expected in the light of a conception that had sunk deeper than we realize into public consciousness: Plato's and Aristotle's great chain or ladder of being. Plato had declared that a rational divinity would surely order the world in such a way as to make an unbroken gradation from the lowest to the highest living thing --- from water flea even to divinity. Any creature that could be rationally imagined must exist in reality (the ``principle of plenitude''), and after all it is not at all difficult to imagine something intermediate between monkey and man. This slot was waiting for apes.

It is customary to say that the propounding of the theory of evolution, that is of the genetic continuity between man and beast, was another great affront to human dignity. If it was so, it did not go deep. For one thing, evolution was already a familiar concept, already widely discussed by philosophers,, writing men, and intellectuals. After all, it was only the great ladder of being that laid down along the time coordinate which is traditionally horizontal.

In any case the affront was not so much to people as to Holy Writ and this was soon got over: it came to be seen that the evolutionary concept was as splendid and dignified and worthy opf being a disposition of God's as the doctrine of special creation, and in any case Man was top animal on the evolutionary scale of variation.

I turn now to considering the prolongation of life by attempting to lengthen the lifespan or by the use of medical engineering. Because he was a deeply religious man, I think it specially significant that Frnacis Bacon in his Valerius Terminus describes the true purpose of science as the discovery of all operations and possibilities of operations from immortality (if it were possible) to the humblest mechanical practice.

Today research on the lengthening of the lifespan is looked down upon as irreverent and antisocial --- antisocial because such a procedure would compound the population problem and to some extent the problem of unemployment. The prolongation of life by something like ten to twenty-five per cent is beginning to be a serious possibility. The life expectancy of mice can be increased by about a quarter by system administration of relatively high doses of industrial antioxidants such as 2-mercaptoethylamine. The interpretation is not yet qite certain for these antioxidants are somewhat toxic and they may prolong life by reducing food intake (a procedure already well known to lengthen life). But supposing they do not act this way; suppose we take the results at their face value. If it is true that systemic doses of reducing agents are beneficial this provides a theoretical foundation for the use, energetically advocated by Linus Pauling and Albert Szent-Gyorgy, of high doses of oral ascorbic acid (vitamin C).

The fear that it is undignified to attempt to prolong life in this way will not bear examinaiton. All medical treatment, even treatments as humble and simple as indigestion pills and plasters such as we apply to cuts --- all such treatemnts if they are effective at all are effective in a way which on an epidemiological scale can be measured by an increase of life expectancy, however minute it may be.

A more lively topic of current discussion is perhaps the use of medical engineering to try to save victims of physica or medical accidents from what would otherwise be certain death. By ``medical engineering'' I mean all the apparatus of intensive care, intravenous feeding, perhaps dialysis as a substitute for kidney function, blood transfusion if necessary, and the mechanical ventilation of the lungs. All this apparatus has been alleged to deprive death of its dignity: it is a ``prolongation of death,'' the critics say rather than a prolongation of life.

I disagree strongly with this view which is deeply unbiological: there is no more deep-seated biological insitnct than that which expresses itself as a firm grasp upon life, there is more dignity, as there is more hamnity, in fighting for life than in passive abdication from our most hardly won and most deeply prized possession.