I challenge the usual approach of defining emergence in terms of properties of wholes “emerging” upon properties of parts. This approach indeed fails to meet the requirement of nontriviality, since it renders a bunch of ordinary properties emergent; however, by defining emergence as the incompressibility of a simulation process, we have an objective meaning of emergence because the difference between the processes satisfying the incompressibility criterion and the other processes does not depend on our cognitive abilities. Finally, this definition fulfills (...) the nontriviality and the scientific‐adequacy requirements better than the combinatorial approach, emergence here being a predicate of processes rather than of properties. †To contact the author, please write to: Institut d'Histoire et de Philosophie des Sciences et des Techniques (CNRS/Université Paris I Sorbonne), 13 rue du Four 75006, Paris; e‐mail: [email protected]. (shrink)