Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The following Essay does not pretend to establish a new theory. Its object is to examine certain typical notions of truth, one or other of which - whether in the form of a vague assumption, or raised to the level of an explicit theory - has hitherto served as the basis of philosophical speculation. If I am not mistaken, every one of these typical notions and accredited theories of truth fails sooner or later to maintain itself against critical investigation. And I have tried, whilst exhibiting the nature and the grounds of their failure.