In this type of submission...
In this type of submission, the body submits, but the mind and reason do not; instead, they are constantly thinking of rebellion, incessantly contemplating how to get a chance to overcome the opponent once again. This is the state of his reason and thought, and as for his feelings and emotions, they too continuously denounce the enemy. This type of submission – that of the body – is the most that can be achieved by force. The next level of submission is the submission of the intellect and reason.
The power that can make the intellect submit is that of logic and reasoning. Here, physical force can’t accomplish anything. It is absolutely impossible through physical force to make a student understand that the sum of the angles of a triangle is equal to two right angles. Mathematical propositions must be proven through reasoning and not through any other way. The intellect is forced to submit through thinking and reasoning.
If sufficient proof exists and is presented to the intellect and the intellect understands it, it submits, even if all the powers of the world say not to submit. It is well-known that when Galileo was tortured for his belief in the movement of the earth and centrality of the sun in the solar system, out of fear that they would burn him alive, he expressed repentance of his scientific view; in that condition, he wrote something on the ground.
The reality of faith is submission of the heart; submission of the tongue or submission of the thought and intellect, if not coupled with submission of the heart, is not faith. Submission of the heart is equal to submission of the entire existence of a person and the negation of every type of obstinacy and rejection. It is possible that someone may submit to an idea as far as the intellect and mind are concerned, but not the spirit.