1) a=a; ‘morning star=morning star’
2) a=b; ‘morning star=evening star’
3) b=a; ‘evening star=morning star’
Frege’s puzzle of identity concerns the identity and semantics of proper names and objects. In 1892 Frege noticed the equation a=a had the same meaning while a=b had the same cognitive value. He believed that, with logic, it is clear that a=a, and with careful examination and calculation that a=b. ‘Morning star=morning star’ is an obvious statement that everyone knows, but no one can know ‘morning star=evening star’ without astronomical investigation. Frege believed that a and b had to be completely identical in order for the statement a=b to be valid. He claims that statements 1 and 2 are “analytic” and “priori” meaning they are guaranteed valid through logic. In statement 2, ‘morning star=evening star’ is true because both names are referring to the same planet, Venus. It’s the same as stating ‘morning star’=’morning star’. However, according to Frege, if the statement were to switch around to create statement 3, ‘evening star=morning star’, it would be unequal to statement 2. Although a=a is like a=b; a=b does not have the same cognitive value to b=a.
According to Frege, there are several reasons why statements 2 and 3 are unequal. Statement 2 is informative and an astronomical discovery to us. Statement 3 is a trivial fact and can be known without work. Frege’s statements are special because while a=a is referring to one thing, a=b is referring to two things. In the