A short, finished list rather than an endless feed: 100 of the best alone quotes ever written, picked out of the full alone archive on QuoteForever. You will find James Madison, Jean De La Bruyere, Martin Luther and Mary Baker Eddy among them.
Read the list top to bottom, or use it as a starting point - every author name links to everything else they said, and every quote has its own page you can share or turn into an image.