The Imperative of Responsibility

Jonas's main work in ethics, subtitled In Search of an Ethics for the Technological Age in the English version of 1984. He argues that modern technology has changed the nature of human action: its effects now reach across the whole planet and far into the future, and traditional ethics, concerned with neighbours in the here and now, has no rules for this. He proposes a new imperative, modelled on Kant's but directed at the future: act so that the effects of your action are compatible with the continued existence of genuine human life on Earth. Because the stakes are so high, he defends a "heuristics of fear": we should give the bad prognosis priority over the good one. Jonas grounds responsibility in a metaphysics of life and value, and takes the parent's care for a newborn as its archetype. The last part criticises utopian hopes, especially Ernst Bloch's Marxist Principle of Hope.

It is one of the founding texts of environmental and technology ethics and a source of the precautionary principle, and it asks what we owe to people not yet born.