The Principia Mathematica (often abbreviated PM) is a three-volume work on the foundations of mathematics written by Alfred North Whitehead and Bertrand Russell. Bertrand Arthur William Russell, 5rd Earl Russell, OM, FRS was a British philosopher, logici 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠 䒠