 The standard argument for (1) is variously referred to as the “thinking animal argument” (Olson 1997, 2003), the “too many minds objection” (S. Shoemaker 1999), the “two lives objection” (S. Campbell 2006), and the “too many thinkers problem” (Parfit 2012: 7). It was developed by Snowdon (1990: 91), Carter (1988), McDowell (1997: 237), and Ayers (1991, vol. 2: 283). It has since been sharpened and popularized by Olson (1997: 106–09, 2003: 325–30, 2007: 29–39). Here it is: