There are two contrasting points of view on what Leibniz meant by "calculus ratiocinator". This algebra would include rules for symbolic manipulation, what he called a "calculus ratiocinator" . Using Mr. Hero's second head (the "Ratiocinator"), Mr. Hero would give advice to the audience. For Leibniz, it would be supported by a calculus ratiocinator. His calculus ratiocinator anticipated aspects of the universal Turing machine. Wiener used the term in reference to "calculus ratiocinator", a calculating machine constructed by Leibniz. Leibniz's calculus ratiocinator can be seen as foreshadowing classical logic. As a computing machine, the ideal "calculus ratiocinator" would perform Leibniz's integral and differential calculus. Hence the "characteristic", "calculus ratiocinator", and encyclopedia form three pillars of Leibniz's project.