The Theory of probabilities is simply the science of logic quantitatively treated. A quote by American logician Charles Saunders Peirce (1839 - 1914). The quote may be found in "Writings of Charles Saunders Peirce, volume 3, 1872-1878" p. 278 as cited in "Statistically Speaking: A dictionary of quotations" compiled by Carl Gaither and Alma Cavazos-Gaither.