Step 1: Understanding Descartes' "Cogito".
Descartes' famous statement "Cogito, ergo sum" ("I think, therefore I am") implies that the existence of the self is certain, even in the absence of any external world or external senses. Descartes uses doubt as a method to prove the self’s existence, asserting that the act of doubting confirms the existence of the doubter.
Step 2: Analyzing the options.
- (A) Self exists as an imperfect thing: Descartes does not claim that the self is imperfect; his focus is on the certainty of the self's existence, not its imperfection.
- (B) Self exists as a perfect thing: While Descartes acknowledges the self’s certainty, he does not assert its perfection in this context.
- (C) Only the world exists: This contradicts Descartes’ argument, as he doubts the existence of the external world, relying only on the certainty of the self.
- (D) Only the self exists: This aligns with Descartes’ philosophy, where the existence of the self (as a thinking being) is undeniable.
Step 3: Conclusion.
The correct answer is (D) because it aligns with Descartes' assertion that the self exists independently of the external world.