Mark Johnston

The prospect of using cell-based interventions (CBIs) to treat neurological conditions raises several important ethical and policy questions. In this target article, we focus on issues related to the unique constellation of traits that characterize CBIs targeted at the central nervous system. In particular, there is at least a theoretical prospect that these cells will alter the recipients' cognition, mood, and behavior—brain functions that are central to our concept of the self. The potential for such changes, although perhaps remote, is cause for concern and careful ethical analysis. Both to enable better informed consent in the future and as an end in itself, we argue that early human trials of CBIs for neurological conditions must monitor subjects for changes in cognition, mood, and behavior; further, we recommend concrete steps for that monitoring. Such steps will help better characterize the potential risks and benefits of CBIs as they are tested and potentially used for treatment.

The main thesis is that sensory experience is not “predicative” but rather “presentational”, and hence cannot be properly modeled by propositional attitudes to the effect that such and such is the case. Indeed, the propostional attitude model not only (i) mischaracterizes the success conditions of experience, it also (ii) occludes the very thing that makes sensory experience epistemically distinctive. Once we see just how the object-directed and “perceiving-as” states make room for the distinctive epistemic significance of perceptual experience, the newly “discovered” propositional attitude—Exing that _p_—will be seen to be not only an ill-fitting, but an idle, wheel, both internally to the theory of perception and more broadly within epistemology. Experiences, understood as attentive sensory episodes, provide us with awareness of the truthmakers for what we often go on to immediately judge. We are thereby often in a postion to ratify our immediate perceptual judgments on the basis of what we have experienced. This is the epistemic virtue that has been occluded by the now dominant idea that perceptual experience is a non-factive relation to a propositional content. The factive attitude model, reminiscent of John McDowell’s view, is also shown to be an inadequate account of the kind of entitlement perceptual experience delivers. Facts are pleonastic, and are “etiolated” in a way that the things we perceive are not.

This chapter raises three objections to animalism. First, if it isn’t an account of what we _essentially_ are then the “too many persons” argument is ineffectual, since “animal” could be a phase sortal. If it is an account of what we essentially are then this needs independent argument, not provided by the “too many persons” argument. Second, the “too many persons” argument threatens animalism, once we distinguish an animal and the brain that is its organ of mentation. Third, animalism has a problem with “remnant” persons, e.g. the person who comes into existence when my head is severed from my destroyed body and lives for a little time, as in a gruesome variant on the guillotine. It looks as if the animalist must say that a person comes into being merely as a non-causal upshot of the destruction of non-neural tissue. Various replies on behalf of animalism are considered and rejected.