The next significant name in the genealogical tree of modern Utilitarianism is DAVID HARTLEY. As it was the distinction of Mr. Locke to have given respectability to the vulgar British prejudice against innate ideas, so the claim of Hartley to reputation rests on his having first given prominence to the doctrine of the association of ideas, a doctrine which from its originator down to the most recent times, plays an important part in every form and phasis of speculative and practical externalism. Hartley was a Yorkshireman, born at Armley, near Leeds, in the year 1705, educated at Cambridge originally for the Church; but having a thoughtful mind and a tender conscience, he did not feel himself in a condition to subscribe the Church Articles in the offhand way which academical morality sanctioned; and accordingly betook himself to the study of medicine, an art which he afterwards practised with success, first in Newark and London, and then at Bath, where he died. These facts are of great significance, as indicating the remarkable combination in his character and works of an extremely sensitive evangelic morality, with a tendency to give physical explanations of spiritual operations, from which evangelic moralists are naturally averse. The object of his great work, _Observations on Man_, published in the year 1749, is to give a complete treatise of human nature on the inductive method of Locke and Newton; and accordingly the first volume, which contains his most peculiar views, is merely a following into detail of the doctrine of Locke, that all our knowledge proceeds from sensation, and that ideas in the brain are the product of impressions on the sensuous nerves. This one-sided notion Hartley {285} pursues into the inmost network and curious membranous wrappings of the brain, and by the action and reaction and interaction of vibrations and vibratiuncles in that region, attempts to explain the generation of thought and reasoning; and this he does through long chapters, and with not a little iteration, in language than which the most extreme materialist could desire nothing more crass. In fact, we find in Hartley the great precursor of those masters of physical science in the present day, who seem to expect some important discovery in mental science from the curious comparison of cerebral structure in the monkey and the man. A few short extracts will make this more obvious. “Simple ideas,” he says, “run into clusters and create complex ideas”--(i. 75.) Here we have that vague use of the word “idea,” which serves equally for a sensation and a thought, and which lies at the bottom of all that strange confusion of thought which runs with such unhappy persistency through all the speculations of Mr. Locke. Again, “Ideas, intellect, memory, fancy, affections, will, all these are of the same original, and differ only in degree, or some accidental circumstance; they are all deducible from the external impressions made on the senses, the vestiges, or