It has recently become clear that we are harming future generations. By our inaction on the climate, by our destruction of nature, by our neglect of health and education; and more generally because we spend more money on the consumption and pensions of today’s working people than on the needs of tomorrow’s youth. And yet: today’s adults would have an interest in the well-being of tomorrow’s young people, who will be working when they are no longer working. Reason should therefore convince them that it is in their interest not to be selfish.

However, the most ancient history, as well as the most recent behaviour, teaches us that reason is not enough to overcome selfishness. From the refusal of the carbon tax in Europe, to the frantic pursuit of gas and oil purchases, from the refusal of the elimination of pesticides and nitrogen fertilizers to the crazy demands of all parties, wherever they may be, on the eve of elections, today’s living people always refuse, if it is harmful to them, to create the conditions of a liveable world for their children and grandchildren.

To prevent this disaster, which awaits us, I have proposed that a simple principle be written into the Constitution of each of our countries, particularly in Europe, as well as into the law of the European Union: “any decision contrary to the interests of future generations is unconstitutional”; consequently, the long-term impact of any decision should be measured before it is validated. I have been told that such a condition is already partly provided for in France by the precautionary principle, that to go further would be to give all the power to the judges, who would not know how to define this interest of future generations, and that all this would lead to arbitrariness and to absurd and undemocratic decisions.

These objections do not hold: the precautionary principle is not, in France, an absolute constitutional obligation, and it has been interpreted as prohibiting, in very rare cases, what may harm the nearest future and not the distant future. On the other hand, the application of the rule I am proposing would not take anything away from the powers of the executive and the legislature; it should just force them to justify to their constituents the very long-term impact of their decisions, even more than they sometimes do today, when they are forced to do so by specific procedures, in particular in the field of urban planning. Naturally, decision-makers could be wrong, and the judge, who will verify the validity of this impact measurement, could also be wrong. But, over time, the accuracy of these analyses will improve and the current attempts to introduce extra-financial accounting measures for companies could feed into the reflection on measures of the impact of public action. The gradual establishment of case law, taken up or modified by the legislator and the sovereign people, will make it possible to take away from the judge this power which he will have had only temporarily.

I even propose (after a conversation with a friend whose son was the victim of a hit-and-run driver) to generalise this principle to all forms of violence against future generations; and to consider as particularly punishable acts any violence against children, any shortage of educational resources that is not justified by unavoidable budgetary constraints. Similarly, it should be considered illegal to purchase materials, spare parts or finished products manufactured elsewhere by imposing violence on future generations, and thus in particular, obviously, by using child labour.

Such a constitutional ban on violence against future generations would soon have far-reaching consequences for the economy. For example, it would no longer be possible to subsidise, as is done today, companies that produce or use, directly or indirectly, fossil fuels, pesticides or artificial sugars.

This should even lead to individual behaviour of the same kind, which should already be that of well-intentioned parents towards their children. We should not then wait until 2050 to implement revolutionary changes, which are long overdue.