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.

All men's misfortunes spring from their hatred of being alone.

There are places and moments in which one is so completely alone that one sees the world entire.

Yes, I guess you could say I am a loner, but I feel more lonely in a crowed room with boring people than I feel on my own.

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

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

A man content to go to heaven alone will never go to heaven.

Always give a word or sign of salute when meeting or passing a friend, or even a stranger, if in a lonely place.

I paint self-portraits because I am so often alone, because I am the person I know best.

When so many are lonely as seem to be lonely, it would be inexcusably selfish to be lonely alone.