  Nevertheless, there is another reply available for the advocate of the Biological Criterion, namely, to deny that personal identity has this purported fit with our practical concerns at all. Instead, while biological continuity preserves our identity across time (this advocate might say), psychological continuity is the relation grounding our practical concerns. This move would still preserve the thought that identity has an impact for ethics, just not the one we thought. As Olson, puts it, if it's right that “the relations of practical concerns that typically go along with our identity through time are closely connected with psychological continuity …, then the Biological Approach does have an interesting ethical consequence, namely that those practical relations are not necessarily connected with numerical identity” (Olson 1997b, 70). Obviously, this would be very surprising for theorists like Butler, Reid, and even Locke to hear, but if we had overwhelming metaphysical reasons to adopt the Biological Criterion, it could well be true. This stance is a version of the Identity Doesn't Matter (IDM) view, to be discussed later.