  The science of complexity is based on a new way of thinking that stands in
sharp contrast to the philosophy underlying Newtonian science, which is based
on reductionism, determinism, and objective knowledge. This paper reviews the
historical development of this new world view, focusing on its philosophical
foundations. Determinism was challenged by quantum mechanics and chaos theory.
Systems theory replaced reductionism by a scientifically based holism.
Cybernetics and postmodern social science showed that knowledge is
intrinsically subjective. These developments are being integrated under the
header of "complexity science". Its central paradigm is the multi-agent system.
Agents are intrinsically subjective and uncertain about their environment and
future, but out of their local interactions, a global organization emerges.
Although different philosophers, and in particular the postmodernists, have
voiced similar ideas, the paradigm of complexity still needs to be fully
assimilated by philosophy. This will throw a new light on old philosophical
issues such as relativism, ethics and the role of the subject.
