Which Irreducible Complexity?

[swamidass (S. Joshua Swamidass)]

We can imagine several types of IC that should not be conflated…

@swamidass

• IC1 – one way to objectively measure the complexity of any system, including biochemical systems, independent of the inference whether or not a specific level of complexity is evolvable.

• IC2 – systems too complex (somehow) to evolve by positive selection alone (e.g. the long falsified theory of Darwinism).

• IC3 – systems too complex (somehow) to evolve by known natural processes alone (e.g. the best current understanding of evolutionary science).

• IC4 – systems too complex (somehow) to evolve by known and unknown natural processes alone (e.g. a total understanding of natural process, forever inaccessible).

• IC5 – systems too complex (somehow) to evolve by known and unknown natural and providential processes (i.e. an empty set with no possible examples).

Christians that affirm evolutionary science, and common descent, know that there are zero systems that are IC5. That is what makes the recent Crossway Theistic Evolution book so strange. They seemed to think that IC5 = IC2, which is transparently false. Though that has to be true for any of their argumentation to make sense.

No one cannot possibly know if there are any systems that are IC4, as this seems like a question outside the bonds of science. It might be extrinsically beyond human knowledge. The ID movement almost never seems to engage IC3, though we evolutionary scientists are always looking at the boundary of IC3 and IC4 to expand our knowledge of evolutionary mechanisms.

Darwinism, though, everyone gave up a long long time ago, except people messing around with straw man arguments of evolution, like that in IC2.