Replacing the ruling of Allah with man-made laws: Is this major shirk or a form of minor shirk?

Question:
Honorable Shaykh, may Allah grant you success. Is replacing the ruling of Allah with man-made laws considered major shirk or a form of minor shirk?

Answer:
The scholars have differed on this issue, as seen in Ibn Kathir’s tafsir. If a person believes that the ruling of other than Allah is better than the ruling of Allah, or equal to the ruling of Allah, and that he has the choice, then he is a disbeliever who has committed major shirk, which takes him out of the religion. However, if he believes that the ruling of Allah is the truth and the ruling of others is false, but he is driven to do so either by worldly greed or because he fears someone, then this is minor shirk. This is because he believes that the ruling of Allah is the truth and that this [ruling of others] is false, but he seeks an excuse for himself in this matter. So this becomes minor shirk. Yes.