Which Consciousness is Responsible for the Function of Thinking?

Thinking is divided into shallow-level thinking and deep-level thinking. Shallow-level thinking is conducted by consciousness alone, which is somewhat superficial and cursory; deep-level thinking involves the joint effort of consciousness and the mental faculty, which requires concentration. With insufficient concentration, thinking remains only on the surface of consciousness and cannot penetrate to the level of the mental faculty, thus failing to achieve genuine understanding or truly resolve problems. In such cases, doubts in the mind remain unresolved.