You cannot be lonely if you like the person you're alone with.

Even in the presence of others he was completely alone.

I love to be alone. I never found the companion that was so companionable as solitude.

If you are lonely when you're alone, you are in bad company.

If it's true that our species is alone in the universe, then I'd have to say the universe aimed rather low and settled for very little.

I don't want to be alone, I want to be left alone.

Look at the sky. We are not alone. The whole universe is friendly to us and conspires only to give the best to those who dream and work.

Only the lonely know the way I feel tonight.

Every man is born as many men and dies as a single one.

All men's miseries derive from not being able to sit in a quiet room alone.