Original: Ludwig Josef Johann Wittgenstein ( 26 April 1889 -- 29 April 1951 ) was an Austrian-British philosopher who worked primarily in logic , the philosophy of mathematics , the philosophy of mind , and the philosophy of language .
Simplified: April 29 , 1951 ) was an Austrian philosopher . He worked mainly in the basics of logic , the philosophy of mathematics , the philosophy of mind , and the philosophy of language .