"The lonely man finds himself surrounded by others with whom he cannot establish contact or to whose hostility he is exposed.
The solitary man, on the contrary, is alone and therefore "can be together with himself." In solitude, in other words, I am "by myself", together with my self, and therefore two-in-one, whereas in loneliness I am actually one, deserted by all others.
All thinking, strictly speaking, is done in solitude and is a dialogue of thought.
Solitude can became loneliness; this happens when all by myself I am deserted by my own self. Solitary men have always been in danger of loneliness, when they can no longer find the redeeming grace of companionship..."