In philosophy, systems theory, science, and art, emergence occurs when a complex entity has properties or behaviors that its parts do not have on their own, and emerge only when they interact in a wider whole.
The formation of complex symmetrical and fractal patterns in snowflakes exemplifies emergence in a physical system.
A termite "cathedral" mound produced by a termite colony offers a classic example of emergence in nature.
Reductionism is any of several related philosophical ideas regarding the associations between phenomena which can be described in terms of other simpler or more fundamental phenomena. It is also described as an intellectual and philosophical position that interprets a complex system as the sum of its parts.
René Descartes, in De homine (1662), claimed that non-human animals could be explained reductively as automata; meaning essentially as more mechanically complex versions of this Digesting Duck.