They based this on a minimum set of 'axioms' or assumptions. That means they weren't just proving that 1+1=2 (under their system of mathematics) but also defined (amongst a lot of other propositions) what '1', '2', '+' and '=' meant.

They spend the treatise defining what was hoped to be a complete and consistent basis for all of mathematics. It is worth noting: Whitehead & Russell don't spend 360-odd pages just adding two numbers together, like you were taught in school. On page 362 there is the quoted claim that Proposition 54.43 provides the basis for 1 + 1 = 2 It isn't until page 359 that the concept of '2' is introduced (as a 'cardinal couple' - it isn't until later that they show that this is equivalent to the cardinal number, 2, that we are familiar with.) this large PDF), we can confirm the claim. The volume also includes two important pieces from his later ethical writings, 'Free will' and 'The conception of intrinsic value', and a new introduction by Thomas Baldwin.If you have only studied mathematics at school, the way it works at university/academic level can be quite alien.īy looking at the original Principia Mathematica, by Alfred Whitehead AND Bertrand Russell (e.g. Though unfinished, it sets out clearly Moore's second thoughts about his own work. Principia Ethica is reprinted here with the previously unpublished Preface Moore wrote for a planned, but never completed, second edition.

It is particularly renowned for Moore's argument that previous ethical theories have been guilty of a fallacy - the 'naturalistic fallacy'. Its influence was first largely confined to the Bloomsbury Group - Maynard Keynes wrote that it was 'better than Plato' - who took it up for its celebration of the values of art and love but later it achieved the widespread recognition it still retains as a classic text of analytic ethical theory. Principia Ethica is recognised as the definitive starting point for twentieth-century ethical theory. Description Product filter button Description

Principia of mathematics