The theory holds that when we reason, we generate models of what is possible given not only the stated premises but also our own knowledge. Our limited working memory makes it difficult for us to think of all possible models, and this limitation, according to Johnson-Laird, is one of our biggest cognitive failures.
We also assume that our mental models only represent what is true, which can lead to systematic fallacies. Some of these fallacies are so powerful that they seem to be cognitive illusions. Such fallacies present a dilemma for theories of reasoning that involve formal rules of inference, because we shouldn’t be making these kinds of mistakes as long as we have valid rules.
Via Sakis Koukouvis