John Stuart Mill (20 May 1806 - 8 May 1873), British philosopher, political economist, civil servant and Member of Parliament, was an influential liberal thinker of the 19th century. He was an exponent of utilitarianism, an ethical theory developed by Jeremy Bentham, although his conception of it was very different from Bentham's. An excerpt from A System Of Logic Ratiocinative And Inductive reads, "Truths are known to us in two ways: some are known directly, and of themselves; some through the medium of other truths. The former are the subject of Intuition, or Consciousness; the latter, of Inference. The truths known by intuition are the original premises from which all others are inferred. Our assent to the conclusion being grounded on the truth of the premises, we never could arrive at any knowledge by reasoning, unless something could be known antecedently to all reasoning."