AB,
The argument is entirely based on the unlikely probability that the unfathomable complexity of the human mind could have emerged from random, unguided, purposeless forces. How is this circular reasoning?
No it isn’t. The argument is actually entirely based on
two propositions, namely:
1. That humans were so unlikely to have appeared by chance that there must have been a god to guide the process; AND
2. That god wanted humans to exist all along.
In other words, your opening premise to do the designing (“god”) and your conclusion to do the guiding (also “god”)
are the same thing.
And that’s called circular reasoning.
Now consider instead our deck of cards. I’ve already told you how fantastically unlikely any given sequence of 52 cards will be. You don’t though also claim that when the cards are dealt there must therefore have been a guiding agency to make them come out that way. Why not? Because in that case you don’t also insert
ab initio an agency who
intended them to come out that way.
This in essence is where you keep going wrong. Work instead on the basis of a universe that neither knows nor cares what life might emerge and there’s nothing especially remarkable about the fact that humans exist. All we can say about that perhaps is “lucky us”, just as, say, a lottery ticket winner may say “lucky me” with no implication that Camelot wanted him to be the winner all along.
Short version: you cannot use the premise “god” to justify the conclusion “god”.
Is the problem clear now?