Human Beings, Human Animals, and Mentalistic Survival

I critically discuss both the particular doctrinal and general meta-philosophical or methodological tenets of Mark Johnston's paper "Human Beings", attending to several weaknesses in his argument. One of the most important amongst them is an apparent reliance on a substitution of identicals within an intensional context as he argues that continuity of functioning brain is essential to the persistence of "Human Beings" as allegedly singled out by his methodology; another equally important is a simple lacuna in place of an argument that candidate entities for re-identification by means we take for granted in the case of persons cannot be what I call "mentalistically" individuated