 What's the name of the religion? Submission. It's not only recognizing that something is true but it's actually submitting yourself and accepting it in your heart. So it's not simply cognitive but it's also spiritual. And this is why the qalb is the seat of Iman, it's not the dimaq. The dimaq is not where Iman is, the qalb is where Iman is. The dimaq recognizes, it engages in cognitive functions, it learns, it processes information. But the heart either submits to what it knows to be true or holds back. And so that holding back to ultimate reality, that's what kufr is. It's once a person recognizes truth and they refuse to submit, whereas Islam or Iman is to actually, it's called a movement of the soul.