"One ought not to write for money, but I consider it a first duty after one has written to exact the highest possible price. It is not a matter which concerns only the writer, but all writers."

Next Quote

There are two famous labyrinths where our reason very often goes astray. One concerns the great question of the free and the necessary, above all in the production and the origin of Evil. The other consists in the discussion of continuity, and of the indivisibles which appear to be the elements thereof, and where the consideration of the infinite must enter in.

— Gottfried Leibniz