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.

Every man must do two things alone he must do his own believing and his own dying.

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

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

Every man must do two things alone he must do his own believing and his own dying.

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

Associate with men of good quality if you esteem your own reputation for it is better to be alone than in bad company.

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

Absolutely lonely people have few personal interactions of any kind.

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