noun
solipsism
SAH-lip-siz-um/ˈsɑːlɪpsɪzəm/
The view that only one's own mind is certain to exist.
Solipsism holds that only your own mind is certain to exist.

Etymology
“Self alone” names the central restriction: only one’s own mind is securely knowable. The term developed from an earlier sense of “egoism” into this philosophical position about the limits of knowledge.
In context
So he's not saying, he's not adhering to solipsism. He admits that you have a conscious inner life, I do, and everybody else does.
More examples
- The professor asks whether solipsism can ever be disproved.
- Her essay challenges solipsism by defending our knowledge of other minds.
- Doubting a news report does not commit you to solipsism.
Forms
solipsism
solipsist noun — A person who accepts this philosophical view.
Similar words
- skepticism
- Questions knowledge broadly without making one's own mind uniquely certain.
- idealism
- Treats reality as fundamentally mental, not necessarily limited to oneself.