Wait–aren’t we already? After all, we can change our features quite radically through surgery, if we have the money and the will. However, these aren’t the changes involved in the sort of shape shifting I have in mind. I’m imagining changing our features using processes that are under the control of our own bodies. Well, actually, I don’t want to count all of the changes that meet that description, as these would include the ordinary sort of growth we all undergo, whereby we look quite different—larger and hairier, for example—than we did when we were very young. The shape shifters I’m imagining can change their shape at will, using bodily processes that are under their control.
Are such creatures possible? Well, there are rain frogs and cuttlefish can quickly change their skin texture. Cuttlefish can also change the color of their skin and the patterns displayed there. Some octopuses can change their color, shape, and texture, and mimic several other species. Hydras can repair drastic damage to themselves by moving its cells around and reassembling them, using a process called morphallaxis. It is reported that if a hydra’s cells are completely disassembled, and piled up, these will move around and form up into a hydra once again. If a creature had the hydra’s capacity for morphallaxis, and were able to control it at will, in much the way that a mimic octopus can change its shape and appearance, then it would have a remarkably extensive form of shape shifting at its disposal.
Of course, even if we can imagine a shape shifting creature, it is not obvious that you and I could become one. There may be no way to transform ourselves into shape shifters. As far as I can tell, we would have to grow different sorts of cells than we have now, and we would have to change our genome. We would have to change it a great deal. That would require developing some extraordinarily sophisticated technology. I am not certain it will ever be done.
These are daunting, but are only practical difficulties. If we aspire to become shape shifters, we also face conceptual difficulties, which come into view when we consider that some of our features are essential to us, in the sense that we could not possibly exist without them. For example, some people would claim that our humanity is essential to us, and that shape shifting is inhuman. If being a shape shifter is incompatible with being human, and being human is essential to us, then we could not possibly transform ourselves into shape shifters. Perhaps applying some sort of technology to ourselves would result in the formation of shape shifters, but it would not be a way of transforming ourselves into shape shifters. Instead, we would end up replacing ourselves with some other creature.
Other people might deny that humanity is essential to us because what we are, by nature, are persons, thought of as self-aware beings whose only essential features are psychological. It is conceivable that a person could retain her psychology after transforming herself into a shape shifter.
I think that this latter view about our nature is mistaken. However, I still think that we could become shape shifters. In Mortal Objects I explain why.