Premise #1 = Irreducibly Complex systems or processes infer an intelligent design.
Premise #2 = There is irreducible complexity in the biochemical makeup of living organisms.
Premise #3 = Therefore, there must be an Intelligent Designer of Life.
“If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.” (Origin of Species).
This argument maintains that certain biological systems are too complex to have evolved from simpler, or “less complete” predecessors, and are also too complex to have arisen naturally through chance mutations.
It supports the idea that an intelligent designer was involved in the creation of life (the theory of evolution requires no designer).
The founder of IC as it applies to Intelligent Design, biochemistry professor Michael Behe, defines an irreducibly complex system as one
“composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning”.
Examples are the complexity of the eye, the blood clotting cascade, or the motor in a cell’s flagellum.
For Deeper Study:
Book 2, chapter 5
On-line lessons 54-59
Live classroom 10