Chemical and physical sciences have profoundly modified the living conditions of mankind, in particular chemistry has played a central role. Its creative power has made available a range of new materials and processes for the transformation of matter. Somehow, however, these have often been perceived as unnatural and opposed to the natural ones. As a result the question of a control by society has become more and more actual. This requires that information be available to the public and to decision-makers for evaluating the potential impact of chemical technology on society. Science (not only chemistry) and its implementation through technology have transformed and will continue to transform society in many ways. Although long term basic research is essential for the progress of our ability to shape the world around us, putting basic knowledge into practice has provided and will continue to provide novel and increasingly powerful technologies giving us new freedoms, new ways of life and new means of action. We must seize the chances they offer.

The development of the environmental protection movement, due at least in part to sloppy operation of industrial chemical plants and to disagreeable (not necessarily harmful) pollutions, has led to the exacerbation of the natural versus unnatural debate. One must at the outset distinguish between the dangerous and the unpleasant (not to speak of the plainly wrong). If quality of life benefits from the containment and elimination of both, only the first is threatening and it can usually be controlled by means of existing technologies; but one has to apply them and pay for it. The environmental protection movement has great merits, but when irrationally implemented and short sighted, it may have very perverse effects. I may cite a particularly tragic illustration: it concerns the pesticide DDT and malaria. The ban on DDT was considered the first major victory for the environmentalist movement in the US. The effect of the ban in other nations was less salutary, however. In Ceylon (now Sri Lanka) DDT spraying had reduced malaria cases from 2.8 million in 1948 to 17 in 1963. After spraying was stopped in 1964, malaria cases began to rise again and reached 2.5 million in 1969! The same pattern was repeated in many other tropical – and usually impoverished – regions of the world.

chemistry suffers particularly from suspicion and rejection on the part of our societies. The suspicion against chemical science and its technological realizations are too often carried by a diffuse fear: there are things that one should not touch, for fear of catastrophy. This myth of an intrinsically “pure” Nature whose harmony would be disturbed by man is underlined by a quasi-religion. But nature is totally indifferent to man, it is not good and not bad, it just is. Here also there is a big misunderstanding. One opposes “chemistry” and “nature”. But, a compound is always chemical, be it natural or not, be it generated by a plant or an animal, or produced in the laboratory. A natural substance has no reason to be less toxic than a synthetic one, which is in fact usually in a purer state. In recent years, Bruce Ames has applied to compounds found in common foods the widely used test that he had developed for determining the carcinogenicity of artificial chemicals. The conclusion was quite startling: “Dietary pesticides (99.99%) all natural”!

Chemistry plays a central role in science and society, both by its place in the natural sciences and in knowledge, and by its economic importance and omnipresence in our everyday lives. Being present everywhere, it tends to be forgotten and to go unnoticed. It does not advertise itself but, without it, those achievements we consider spectacular would not see the light of day: therapeutic exploits, feats in space, marvels of technology, and so forth. Even the all-important process of the fission of the atom has been a chemical discovery. Chemistry contributes to meeting humanity’s needs in food and medication, in clothing and shelter, in energy and raw materials, in transport and communications. It supplies materials for physics and industry, models and substrates for biology and pharmacology, properties and processes for science and technology.

Chemistry has traced its path in the history of the universe. In the beginning was the Big Bang, and physics reigned. Then chemistry came along at milder temperatures; particles formed into atoms; these united to give more and more complex molecules, which in turn formed aggregates and membranes, defining primitive cells out of which life emerged.

Chemistry is the science of matter and of its transformations, and life is its highest expression. It provides structures endowed with properties and develops processes for the synthesis of structures. It plays a primordial role in our understanding of material phenomena, in our capability to act upon them, to modify them, to control them and to invent new expressions of them . Chemistry is also a science of transfers, a communication centre and a relay between the simple and the complex, between the laws of physics and the rules of life, between the basic and the applied. If it is thus defined in its interdisciplinary relationships, it is also defined in itself, by its object and its method.

In its method, chemistry is a science of interactions, of transformations and of models. In its object, the molecule and the material, chemistry expresses its creative faculty. Chemical synthesis has the power to produce new molecules and new materials with new properties. New indeed, because they did not exist before being created by the recomposition of atomic arrangements into novel and infinitely varied combinations and structures. By the plasticity of the shapes and functions of the molecule and the material, by its creative power as well as its role as a relay, chemistry is not without analogy to art, a process of transfer by the created work.

Chemistry has been evolving over the years towards an increase in complexity and in diversity, from molecules to materials, from structures to architectures, from properties to functions. Thus, beyond the molecule one witnesses the emergence of a supramolecular chemistry, the chemistry of molecular assemblies, of self-organizing systems and of complex functions. In addition to the exploration of the interface with biology, a definite emphasis lies in non-natural species, possessing a desired chemical or physical property. It opens wide the door to the creative imagination of the chemist at the meeting point of chemistry with biology and physics.

Thus, chemistry is a science and an art. But it is also an industry: each scientific component of the discipline has its industrial counterpart. It has for this reason a very marked impact on economic and social life. It is not surprising that it is called upon more and more often to face a number of new, or increasingly important, socio-economic imperatives associated with geopolitical phenomena. Some result from new economic conditions in the industry – costs and availability of raw materials and energy – others from the reorientation of the chemical industry (the necessity to produce products with high added value, possessing new properties), and finally still others from social preoccupations concerning the environment and the quality of life, such as improvements in working conditions, the safe use of products, the protection of the community, the fight against pollution. Each aspect of human activity therefore depends upon a better knowledge of chemistry and on its progress, and can be improved by it.

This being said, it is clear that chemical industry, like any large scale human activity, must avoid degrading the natural environment whether for reasons of toxicity, simple unpleasantness or even on aesthetic grounds. A plant can perfectly well function without emitting unpleasant fumes or odours if one wants to do so and is prepared to pay for. If it is imperative that industrial activity be both not dangerous and not unpleasant, it is unfortunately not always possible to accurately assess the risks. These deficiencies are a further incentive for pursuing research, but more knowledge does not solve everything. Between a clear danger and a possible risk the choice is easy. Between pleasantness and risk, it is much less so. Zero risk does not exist. Risk appears with life. Zero risk is a dead world. The desire to systematically eliminate all risk may also become a threat to freedom and democracy. It may lead to the elaboration of vast sets of regulations, that are justified or not, but usually anyway insufficient, and that may hinder our freedom of action. At a certain stage, regulations become an unacceptable limitation to freedom. Of course, the answer is not to go back to the past, but one should not forget that Pasteur experimented his vaccine against rabies in conditions that would make one shudder today. Similarly, it has become common place to say that such a fabulous drug as aspirin, which is working wonders one continues to discover, would probably not pass the regulations in vigor today. Like for Pasteur’s vaccine, it was a gamble which in present days appears quite dangerous but which, placed in the context of the time, was justified. One may take all possible precautions, every decision implies taking a risk. Later, in the light of new knowledge acquired, some decisions may be seen as a tragic error, but history cannot be rewritten and the mere fact of living is taking a risk! Our duty is to optimize the chances and minimize the risks. In chemistry, like in all other sciences, a glass that is half-full to some people, is half-empty to others; but the full half, one can drink, whereas with the empty half one cannot do much (except try to fill it)! The much talked-about precautionary principle is a dead-end. And doing nothing can be a much greater risk than doing something!

An attitude that some adopt is to say “Let’s not pass on to our descendants the consequences of our errors”. There is evidently a very judicious side to this, provided it does not induce a precautionary attitude that would lead to stopping research and thus deprive future generations of knowledge that will be very useful to them. Our descendants will continue to evolve intellectually, culturally, materially. They may with hindsight, adopt points of view quite different from ours. To stop the machine would deprive them of the possibility of further development and would prevent them from succeeding where we failed. This is our responsibility, we have no right to force them into such a situation and to hand down judgments in their place. They may be wiser than we are.

However, despite all these reservations, environmentalists have played and do continue to play an important role. They have brought forward certain drifts that may become dangerous; they have led people to reflect and not to be carried away by the fascination of progress at all costs. Would this awareness have been gained without them? Perhaps, but probably more slowly and less clearly.

A very actual issue concerns the attitude of the scientist , of course of the chemical scientist as well, with respect to ethics and society. It is my strong opinion that the scientist has first of all general responsibility to the truth and only then is there responsibility to the society and the world at the particular time in history. Ethics is a function of time, location and knowledge. Pursuit of knowledge and truth supersedes present considerations on what nature, life or the world are or should be, for our own vision can only be a narrow one. Ethical evaluation and rules of justice have changed and will change over time and have to adapt. Law is made for man, not man for law. If it does not fit anymore, change it.

Some think that it is being arrogant to try to modify nature; arrogance, however, is to claim that we are perfect as we are! With all the caution that must be exercised and despite the risks that will be encountered, carefully pondering each step, mankind must continue along its path, for we have no right to switch off the lights of the future.

These perspectives for the future of science -not just for chemistry, but for all science- have already been expressed in most fitting terms by this quintessence of the artist-scientist, Leonardo da Vinci, when he wrote:

«Where nature finishes to produce its own species, man begins, using natural things, with the help of this nature, to create an infinity of species».