"Archimedes sought only a firm and immovable point in order to move the entire earth from one place to another." ("Archimedes, in order that he might draw the terrestrial globe out of its place, and transport it elsewhere, demanded only that one point should be fixed and immovable ...") (Meditation I, IP3 45b)

"Surely great things are to be hoped for if I am lucky enough to find at least one thing that is certain and indubitable." ("... in the same way I shall have the right to conceive high hopes if I am happy enough to discover one thing only which is certain and indubitable.") (IP3 45b)