It is the name given to the path followed in guidance (irshād) and instruction. The third meaning is that, in theoretical (nazari) sciences, it refers to the system of belief to which a person adheres. (Mizān, 162)
Madhhab (school of thought) is one of the views that are believed in. Regardless of the situation, every person is addressed with tālim (instruction) and irshād (guidance). The person who possesses that view defends it. This madhhab may be Ashʿarī, Muʿtazila, Karrāmiyya, or another madhhab. The predecessors, when asked whether there is only one madhhab or three, unanimously agreed that it is not permissible to believe there are three, but rather one must believe there is only one. (Mizān, 164)
The reason why this name is given to the madhhab in the sense of a path is because it is the path that is followed in that madhhab. Thus, since the lover is the very image of the beloved, all material forms also return to Him. The world of sensation (feeling) is in constant connection with the levels of imagination (hayāl) and meaning, so that all these, up to the nafs (the lower self) of Him in all forms, are encompassed.