Commentator: Human behavior cannot be fully understood without inquiring into nonphysical aspects of persons. As evidence of this, I submit the following: suppose that we had a complete scientific account of the physical aspects of some particular human action -- every neurological, physiological, and environmental event involved. Even with all that we would obviously still not truly comprehend the action or know why it occurred.
The flaw in the argument's reasoning is that the purported evidence cited in support of its conclusion presumes that the conclusion is true.