By what do you mean central theorem? I don't follow. Do you believe that a man changes his belief because he takes two competing ideas, puts them under the miscroscope, tries to disprove both of them and walks away with the one that most withstands his mental assaults? Is that the process by which the average man comes to his worldview? Or is the process more akin to getting hold of the first idea that sounds plausible and running with it to the grave?
Both and neither. Central theorem is the theorem that people take ideas weigh the pros and cons, benefits, merits, etc in a reasonable but not always completely rational way, and the peripheral theorem is that people's attitudes change though taking clues and associating positive or negative attitudes with less cognitive clues such as heat, color, size, attractiveness of the presenter etc.. Both work at the simultaneously but one or the other can be more prevalent at different times, with different stimulus and different expectations of that stimulus.
I can't find the book, but I was listening recently to a philosopher who was speaking over the philosophy of science and he pointed out that those who triumph the scientific method as the hallmark of rational thought and scientists stick to this method with iron rigidity are very wrong. Scientists themselves use hunches, faith, are stubborn about theories, etc. In short, to claim that people neatly march down the steps of the scientific method and arrive at a dry rational and unemotional answer is false BUT rationality does play a part and can play a big part in people's thought processes, attitudinal changes, and behavior changes.
So the atheist who says that they rationally looked at the all the arguments and coolly decided that atheism was the most logical based on some kind of Vulcan mind meld process they did is not telling the whole truth, but to say that men are predominately people of feeling with occasional sparks of rationality isn't a complete picture either.
As with almost all things, the correct answer is .... it depends.