Of all the various arguments circulating against the concept of Intelligent Design, there's one aspect of it that I rarely hear expressed.
Adherents of ID use a rather facile analogy comparing a watch to a living organism. If a watch needs a watchmaker, they argue, than it follows that a living thing requires a Creator. They are quick to point out that "Creator" does not necessarily mean the Christian God.
Let's ignore, for a moment, the fallaciousness of the analogy comparing an inanimate object to a being comprised of living, self-replicating cells. And let's give them the benefit of the doubt on the Creator ≠ God bullshit rhetoric.
Let's take the claim at face value: a complex being/system requires a Creator.
Well, then, who created this Creator?
This is a slight variation on the question probably posed by every 5-year old forced by their parents to go to church. When I was around that age and asked my mother that question in reference to God, I got the standard cop-out answer: no one created God, he just always existed.
But if the main arguments to justify the need for the concept of a Creator in the first place are that life cannot have started from non-life and that humans are too complex to have evolved by chance, then the question has to be posed in terms of the Creator itself. Presumably the Creator would have had to have been pretty darn complex itself to have created, or even just initiated, such complexity. How, then, could it have just "always existed" or sprung up from nothingness? How could the Creator have not been "designed"?
And if you allow that the Creator sprung up from nothingness or wasn't itself designed, then why can't you allow that to apply to life? Science gives us all kinds of theories that describe and explain how life did arise from non-life and how organic complexity can be achieved through genetic anomalies and errors and, yes, by chance. What does Christianity or Intelligent Design give us to explain the means by which their respective Creators (who are not the same, remember) were created?
[sound of crickets chirping]