Frege's productive career began in 1879 with the publication of a pamphlet with the title Begriffsschrift , which we can render into English as 'Concept Script'. The pamphlet marked an epoch in the history of logic, for within some hundred pages it set forth a new calculus which has a permanent place at the heart of modern logic. The concept script which gave the book its title was a new symbolism designed to bring out with clarity logical relationships which were concealed in ordinary language. For generations now the curriculum in formal logic has begun with the study of the propositional calculus . This is the branch of logic that deals with those inferences which depend on the force of negation, conjunction, disjunction, etc.
Nobody knows everybody' and 'Any schoolchild can master any language'.
These branches of logic had been studied in the Middle Ages, and have been studied again in the present century in the light of his innovations. In the Begriffsschrift and its sequels Frege was not interested in logic for its own sake. His motive in constructing the new concept script was to assist him in the philosophy of mathematics. To answer this question, Frege set himself the task of seeing 'how far one could get in arithmetic by means of logical deductions alone, supported only by the laws of thought'. Kant had maintained that the truths of mathematics were synthetic a priori , and that our knowledge of them depended on intuition.