TABLE 1.

Major features of emergence in general.

1. Emergence is a property of complex systems, with many interacting parts

a. The interactions are processes, so processes are important (not just the physical parts)

2. Aggregate system functions that are not present in the parts alone

a. Whole is more than the simple sum of the parts; is not reducible to its individual parts

3. Hierarchical arrangement of different levels

a. Novel properties emerge in the system as higher levels are added

b. Emergent properties are novel properties

c. More novelty emerges if the system elaborates or evolves further

d. If the hierarchical system elaborates, there is more specialization of its parts and levels, both structurally and functionally

4. Reciprocal connections exist among structures within and between levels of the neural hierarchy

a. Circular causality: Lower levels bring about the higher levels, which then influence the lower levels (Salthe, 1985: Rothschild, 2006; Bedau, 2008; Nunez, 2016; Koch, 2019); and structures within the same level also influence each other via extensive reciprocal connectivity

5. Constraints:

a. The whole—and the emergent features of the system—constrain what the parts can do or be, and vice versa

b. External environment also constrains the whole and parts

c. Increasing a system’s complexity (more emergence) involves pruning the possibilities (Morowitz, 2002) to only those that let the system persist

6. There are multiple routes to an emergent end-phenomenon, from different sets of lower-level features (Bedau, 2008, pp. 181–182; Koch, 2019, pp. 122–124)