Minimizing Maximality

Judgments about the locus of synchronic personal identity are often guided by the intuition that “I” am the thing that thinks, or minimally, that neither my body nor any part of it is a thinker distinct from me. Ted Sider argues in a series of articles that in order to reconcile this intuition with the principle of microphysical supervenience, we must accept ‘being a thinker’ as a maximal property. Michael Burke extends this conclusion to justify animalism’s claim that the human animal, rather than the brain, is the thinker (and thus the seat of personal identity). I argue first that a scientific account of parthood, rather than property maximality, is the proper way to reconcile microphysical supervenience with the thinker thesis. Second, even if one accepts maximality, it cannot be applied to determine whether the brain qualifies as a thinker, rather than just the locus of an animal’s thought. Whatever else I may be, I am a thing that thinks. Presumably, I am the only thinker that thinks all and only my thoughts. The brain seems to be the locus of thought; am I therefore a brain? Perhaps I am the whole human animal, possessing a thinking brain as a part. But on what grounds could the whole animal be considered a thinker to the exclusion of the brain? We can complicate the matter even further: if the whole human animal counts as a thinker, it is in virtue of having a thinking brain as a part. Whether or not the animal has a left big toe is surely irrelevant to its being a thinker, but then why consider the whole animal, rather than a slightly abbreviated (sans left big toe) animal, the genuine thinker? Only one of these candidate entities can be the genuine thinker, since they are not identical to each other and I am identical to the thinker. But what criteria can we use to identify the winning candidate? Put another way, how are we to determine which entity has the property ‘thinkerhood’? In a recent article,1 Ted Sider argues that this ‘thinker dilemma’ can only be 1‘Maximality and Intrinsic Properties.’ Philosophy and Phenomenological Research 63 (2001): 357-364.