There is one sense in which man is changing very quickly. The man-in-the-street today is mentally a very different being from his counterpart of even two hundred years ago. He may be born much the same, but he has been moulded by a very different world. It is a world which, in spite of all our disastrous muddles and quarrels, is coming more and more under our control. And clearly in so far as we control man's environment, we control human nature itself, at least in a superficial sense.

But further, we have our clever biologists and our bold eugenists. They want to control man's inborn nature, too. Already they have learnt a few surprising tricks, and probably within a century or two they will have learnt many more.

Almost certainly, then, attempts will be made sooner or later to remake man, not only superficially, by changing his circumstances, but radically, by selecting and influencing the germ cells of successive generations.

Now "remaking" man may very easily turn out to be mere monkeying with man. There are two kinds of monkeying. Either you may know what improvements you want, and not know how to produce them; or you may know the technique, without knowing what it is you really want to do. In the case of man, both these dangers are very great.

The problem of technique we must leave to the scientists, bearing in mind, however, the kind of alterations which may be possible, sooner or later. Tonight let us consider whether human nature ought to be changed at all, and if so, in what direction.

Well, I for one am sure that our present human nature needs altering. I can think of many ways in which I myself, for instance, might be better than I am. And my wife would probably welcome even more radical alterations in me.

The general direction of desirable changes I would summarise in this way. They should afford me a richer, wider, deeper, more subtle, more accurate experience of this amazing world. Further, they should help me to see more clearly what is really desirable. Finally, they should enable me, in every kind of situation, to take all relevant facts into account, and behave always with supreme tact, intelligence, insight, foresight, so that always the best possible results may follow. That I should be remade, or you, is impossible. But do we not desire that a race of beings far happier and more vital than ourselves should some day occur? I for one hope that the creation of such a race will become in time the constant policy of all mankind. And though this radical remaking of man is not practical politics to-day, already some of the preliminary steps need no longer be dismissed as fantasy.

There is one obvious way in which either man himself or his world must be improved. Little by little the great diseases, such as cancer, tuberculosis, heart-disease, digestive disorders, nerve and brain disorders, must be abolished. So must all the special troubles of women. And maternity must cease to be a grievous burden. We must create a race gifted with the health and vitality, the beauty and perennial youth, of the mythical heroes.

This leads to the question of longevity. If only we could keep young, most of us would certainly desire to live much longer than the normal span. But from the point of view of the race, and of the far future, would it really be good that the lives of individuals should be longer? The brevity of human life certainly enables the species to keep on starting again with a clean slate. Think of whatever historical period you most despise. How lamentable if that generation had occupied the earth for ever! On the other hand, very much of our short life-time is spent in merely overtaking our seniors. And no sooner have we become properly equipped for carrying on the work of the world than our powers begin to fail.

From the racial point of view, then, two complementary improvements are needed. In the remote future, when the race has reached its prime, the individual must live much longer than is possible today, say a thousand times as long; but also his youthful suppleness and vigour must continue till death. In fact senility, not only extreme senility, but that blunting of percipience and slow dying of the mind, which with us begins before middle life, must be abolished.

It is not desirable that the individual should live for ever, since that would prevent any further improvement in the inborn nature of the species.