THE NEW LOGIC

Evening Star, Issue 21745, 13 June 1934, Page 13

THE NEW LOGIC

CHANGE IN METHOD AMD THEORY OR f H, FINDLAY’S ADDRESS Under the auspices of the Otago Institute, Dr J. N. Findlay, professor of philosophy, gave an address at the Museum last evening on the subject, ‘Modern Tendencies in Logie.’ Professor Hercut presided, dud introduced the speaker. " Dr Findlay' gave an account of a change in Ibaical method find theory which had taken place in the course of Hie last century and was now at iippinging upon text books and university lectures. ' The new view of logic was a result of exact symbolism. Just as progress in mathematics depended oh the, development of mathematical syrnbollsm, so progress in. logic appended oh the development of logical symbolism. The greyth' of logic was arrested for centuries by the attempt to express all logical principles in ordim ary language, Reibpi* was the first philosopher to attempt to devise a calculus pf reasoning, and a istipa universalis, or universal language ip which all philosophical propositions could be expressed, His idea was not developed to any ex cut till George Boole laid the foundation of the logic of classes in hi» ‘ Law of Thought,’ published in' 1846. This logic of classes was perfected by Jevons. and Schroder. Logicians were inspired by this work to elaborate the more fundamental logic of propositions. The German logician Frege, making use of the .concept of “ prositional functions, showed how the logic of classes could be derived from the logic of propositions. A very important branch of logical theory, the logic of relations, was developed by the American logician, 0. S, Pierce. All these streams converged in the great “ principle Mathematjca ” of Russell and Whitehead, _ published in 1911, in which all the principles of logic were deduced from a few simple notions and assumptions, and all the principles of mathematics were then shown to be pure logic and nothing more. Another important development pi the new logic was the tjieorj l of nopmathematieal probabilities, whose foundations were laid by J, M. Keynes in his ‘ Treatise on Probability,’ published in 1921. It Was unfortunate that Mr Keynes had become so absorbed in prescribing for the economic ills of the world that ho was unable to remedy several flaws in his demonstrations.

The philosophical theory of the new logfo went hack to_ Bolzano’s 1 Wissenßchaftslehre,’ published in 1837, and completely ignored at the time. It had been further developed by Frege, Mr Russell, Meinqng in his object-the-ory, and Husserl in bis early logical investigations, Latterly a new theory Of the philosophical basis of logic hod been propounded by Wittgenstein in his ‘ Tractotijs Logico-Phdosopliicns.’ This theory had received the imprimatur of Mr Russell, and was being de-

veloped by philosophical schools. in Cambridge, Berlin, and Vienna. Altogether the new ' logic might be described as a revolution' in philosophical thought. Dr Findlay was accorded a hearty vote pf thanks for bis address.