- Locke famously wrote “And as far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person, it is the same self now with this present one that now reflects on it, that this action was done.” This and similar passages have been interpreted as providing a memory criterion for personal identity.
- Lockeans, as well as their critics, have pointed out that the memory criterion is likely to mean that none of us were ever fetuses or even infants due to the lack of direct psychological connections between then and now. But what has been overlooked is that the memory criterion leads to either
- backward causation1 and a violation of Locke’s own very plausible principle that we can have only one origin, or
- backward causation2 and a number of overlapping people where we thought there was just one.
- I will argue that such problems cannot be avoided by replacing direct psychological connections with overlapping chains of connectedness – what has been called “psychological continuity3.” The most famous account of psychological continuity4, that of Derek Parfit, will still fall prey to these problems for he understands psychological continuity5 to consist of overlapping chains of strong psychological connectedness, the latter defined as involving “at least half the number of direct connections that hold, over every day, in the lives of nearly every actual person.”
- Moreover, even if these problems can be avoided by some revamped account of psychological continuity6, it will not do justice to what is Locke’s insight - recognized by David Lewis as well as Parfit - about the importance to our identity of our consciousness being directly extended into the past.
Text Colour Conventions (see disclaimer)
- Blue: Text by me; © Theo Todman, 2018
- Mauve: Text by correspondent(s) or other author(s); © the author(s)