[...]depending on such 'objective' evidence would seem to put us in the position of saying that someone with Tourette, say, may have a mitigating excuse once we know about basal ganglia abnormalities but not before, although here I imagine Ciurria might rely on 'epistemological luck' and say there may be cases where mitigating factors were present, we just did not know enough to know that they were. [...]Ciurria can go on to say that According to influential thinkers throughout the history of philosophy, traits of personhood are the source of human dignity and intrinsic value, and what separate human beings from animals (e.g., Kant, Anderson 1993). [...]it is important not to deprive people of these qualities unnecessarily or on purely conceptual grounds.