DISSERTATION ON THE PROGRESS OF ETHICAL PHILOSOPHY, CHIEFLY DURING THE SEVENTEENTH AND EIGHTEENTH CENTURIES. [Originally prefixed to the Seventh Edition of the Encyclopædia Britannica.] INTRODUCTION. THE inadequacy of the words of ordinary language for the purposes of Philosophy, is an ancient and frequent complaint; of which the justness will be felt by all who consider the state to which some of the most important arts would be reduced, if the coarse tools of the common labourer were the only instruments to be employed in the most delicate operations of manual expertness. The watchmaker, the optician, and the surgeon, are provided with instruments which are fitted, by careful ingenuity, to second their skill; the philosopher alone is doomed to use the rudest tools for the most refined purposes. He must reason in words of which the looseness and vagueness are suitable, and even agreeable, in the usual intercourse of life, but which are almost as remote from the extreme exactness and precision required, not only in the conveyance, but in the search of truth, as the hammer and the axe would be unfit for the finest exertions of skilful handiwork: for it is not to be forgotten, that he must himself think in these gross words as unavoidably as he uses them in speaking to others. He is in this respect in a worse condition than an astronomer who looked at the heavens only with the naked eye, whose limited and partial observation, however it might lead to error, might not directly, and would not necessarily, deceive. He might be more justly compared to an arithmetician compelled to employ numerals not only cumbrous, but used so irregularly to denote different quantities, that they not only often deceive others, but himself. The natural philosopher and mathematician have in some degree the privilege of framing their own |