الفهمُ كالعين؛ فبينما يجعلنا نبصر كلّ شيء ونُدركه، لا يلتفت إلى ذاته، ويحتاج إلى حيلةٍ وجهدٍ ليُبعد نفسه ويجعل من ذاته موضوعًا له.

“Understanding like the eye; whilst it makes us see and perceive all things, takes no notice of itself; and it requires art and pains to set it at a distance and make it its own subject.”John Locke — Philosophical Works: Preliminary discourse by the editor. On the conduct of the understanding. An essay concerning human understanding (1872)