This thinker formalized a statement of equinumerosity that George Boolos later identified as Hume’s principle. (10[3])This thinker (-5[1])wrote two (10[1])essays criticizing David Hilbert’s lecture on geometry for relying on the demonstration of consistency. This thinker introduced the turnstile symbol to logic in a book that criticizes Kant’s claim that 2 + 3 = 5 (-5[1])was unprovable. (-5[1])Michael Dummett attributes the beginning (10[1])of the linguistic (-5[1])turn (10[1])to (-5[1])this (-5[1])thinker’s (-5[2])use (-5[1])of (-5[1])the (10[1])context principle (10[1]-5[1])while discussing (10[1]-5[1])the origin of numbers. (10[2])This thinker’s (-5[1])Basic Law V (10[5])(“five”) was shown to be (10[2])flawed (10[4])when considering sets through Russell’s paradox. (-5[1])A (10[1])puzzle at the start of a paper (10[1])by this thinker notes “Hesperus (10[1])is Hesperus. (10[1])Hesperus is Phosphorus.” (10[4])For 10 points, name this German (10[1])philosopher (-5[2])who wrote The Foundations (-5[1])of Arithmetic (10[1]-5[1])and On (10[1])Sense and Reference. (10[2]-5[1])■END■ (10[14]0[42])