...philosopher, a native of Samos, bom before the middle of the sixth century before the Christian tero. He visited Egypt ; and derived a portion of his philosophy...discovered the proof of the proposition, that the square en the hypotenuse of a right-angled triangle is equal to the sum of the squares on the other sides....

...what can be got out of them, and nothing else." To quote an example which the author himself gives, the proposition that "the square on the hypotenuse of a right-angled triangle is equal to the sum of the squares on the other two sides" is a categorical proposition, and is not...