Original: Sir Karl Raimund Popper , CH FRS FBA ( 28 July 1902 â '' 17 September 1994 ) was an Austro-British philosopher and a professor at the London School of Economics .
Simplified: Sir Karl Raimund Popper ( 28 July 1902 â '' 17 September 1994 ) was an Austrian and British philosopher and a professor at the London School of Economics .