Gerard Debreu’s speech at the Nobel Banquet, December 10, 1983

Your Majesties, Your Royal Highnesses, Ladies and Gentlemen,

Many Laureates before me must have been filled with wonder at the dazzling recognition they received in Stockholm for something that they enjoyed so much doing. The instant at which a scientist becomes certain that his problem is solved, the following days in which details are worked out and consequences unfold, even the preceding weeks or months of research are sources of unsurpassed, addictive intellectual pleasure. Magnificent rewards for that pleasure may indeed cause astonishment.

Yet a scientist knows that his motivations are often weakly related to the distant consequences of his work. The logical rigor, the generality, and the simplicity of his theories satisfy deep personal intellectual needs, and he frequently seeks them for their own sake. But here, as in Adam Smith’s famous sentence, he seems to be “led by an invisible hand to promote an end which was no part of his intention,” for his personal intellectual fulfilment contributes to promoting the social interest of the scientific community. The logical rigor of his theories provides a secure foundation to build upon; their generality makes them applicable to a broad class of problems; their simplicity makes them usable by a great number of research workers.

It was my great fortune to begin my research career at a time when economic theory was entering a phase of intensive mathematization, and when, as a result, the strength of that invisible hand became irresistible.