[Music] are you the same person you were a year ago 6 months ago are you the same person as you were when you started watching this video more importantly how do you know what are the criteria for continued personal identity which is to say what makes you the same person over time if indeed you are one of the first philosophers to have a crack at this in the modern era was John Lock who had an enormous nose he said that identity of persons is identity of Consciousness your body replaces bits all the time and you could even lose part of your body and still be the same person it even seems like it's logically possible to change your body entirely and still be the same person what stays the same in those scenarios is your mind specifically your memories now it's tempting to include desires hopes beliefs dreams and so on but you could change your desires hopes beliefs dreams and so on and still be the same person so it looks like psychological continuity which is to say memory basically is the Criterion we need for personal identity you are the same person you were a year ago because you remember being that person this idea requires one additional modification courtesy of Thomas Reed Reed asked us to imagine a young boy who becomes a young officer who becomes an old General we'd like to say that's all one person but the old General might not remember being the young boy his memories might have faded with time Reed said that's okay he so long as the general remembers being the officer and the officer remembers being the boy then we have a chain of Memories stretching back into the past and that is enough to establish psychological continuity that seems like a pretty acceptable view I mean it means if you lose all your memories you're no longer the same person as you were so Jason Bourne is not actually the same person as David Webb total Amnesia is basically just death and you might have some different intuitions about that but you can see why it's an attractive Theory but there are counter examples to this imagine you got in a transporter and instead of teleporting you it duplicated you so one person walks out the other end and one person stays exactly where they are a scenario you'll be familiar with if you've ever seen season 6 episode 24 of Star Trek the Next Generation now you might be thinking why I should be worried about that that's clearly something that would never happen in the real world well it is logically possible which is to say it's not contradictory when we imagine it and we are trying to find The Logical connection between the concepts of personhood and identity so indulging in a little science thought experiment can actually be very useful suppose reer gets into the transporter splits and becomes will reker and Tom reker both will and Tom remember being the original reiker they are both psychologically continuous with him but they cannot both be identical with him because identity is what philosophers call a transitive relationship if a is identical to B and B is identical to C then A and C must also be identical and you can see this for yourself if Snoop Dog is Snoop Lion and and Snoop Lion is snoopzilla then Snoop Dog and snoopzilla must be the same person so if reker is identical to Tom reer and will rer Tom and will must be identical to each other but they're not they have different properties will might be on the bridge whilst Tom is in 10 forward Tom might be slightly more beardy think back to our episode on cartisian dualism where we talked about liet's law if two things are identical they must have all the same properties which includes their position in space so Tom and will are psychologically continuous with the original Riker but they are not identical with him psychological continuity cannot be the Criterion for personal identity so what does make you the same person over time Derek pford said that the answer is psychological continuity again what rather than abandon the notion of memory being important for determining who's who parit says that we should abandon the notion of identity identity is a strict onetoone logical relationship and it ties us down when what we're really worried about isn't identity it's survival the question isn't will I be numerically identical to some future philosophy tube presenter the question is will I survive what parfit thinks we should recognize is that one person might survive as two so neither Tom nor will are actually identical with the original reker but Rea does survive as both of them because his memories survive parit tries to demonstrate this by taking the vision case and flipping it on its head he asks us to imagine what would we say in a scenario where two people fused you'd take two sets of desires and beliefs and hopes and put them into one body now certain members of those two sets are likely to be contradictory so some of them will get eliminated from the final product say Vegeta and Goku did Fusion dance and become Gogeta now before the fusion Goku's favorite food was rice and vegetas was egg rolls and when they fuse gogeta's favorite food is egg rolls that means there is more of Vegeta in Gogeta Gogeta is more like Vegeta than he is like Goku now what parit thinks this shows us is that it's survival that we're really worried about when we're talking about whether somebody is the same over time and that survival is a matter of degree you can survive more or less unlike identity which is a strict transitive All or Nothing deal of course what that means is you can be the same person as you were in every relevant sense whilst also not being strictly identical to them which is kind of weird and a lot of philosophers think that's a little bit too weird which is why the debate goes on what do you guys think what makes you the same person over time if indeed you are is parit right that it's survival and not identity that we're really bothered about send me your questions comments queries and comebacks underneath the video on Facebook Twitter or by email there were a lot of votes last time to do an episode on Aesthetics and it was really really close so I think the next episode will be about is Beauty in the eye of the beholder subscribe to join the floss fans and leave a like if you all right time to start filming today's episode I'm just as a quick side note do you remember that collaboration video I did with blink pop shift on whether or not YouTube poops are art some people have actually taken those videos and made YouTube poops out of them I'll put links in the description and my day has been made that's just so so cool so funny I'm so flattered that somebody took the time to do that I feel like I've arrived on on YouTube now this is like when you get your own Wikipedia page anyway um let's see what the phans had to say about weakness of will Fraser Greenie Claudius CL and ilen Bob have all said that maybe weakness of the wheel comes from a failure to place long-term benefit over short-term benefit that's a good idea but it's possible to construct some counter examples to that say you had to make a choice between eating an apple now or eating dessert later you judge that eating the Apple now would be best but you wait and you have dessert anyway in that case you've got weakness of will as we defined it but it's weakness in favor of the long-term benefit rather than the short-term sinsky bro CA and several others all said that maybe weakness of will comes from outdated heuristics modes of decision- making which we are stuck with as a result of how our brains evolved that is a really interesting idea that would actually lend some support to the thing we were talking about at the end of the last episode when we say maybe weakness of wheel is characteristically irrational so you decide to do one thing and judge that that would be best and then your brain's just like nope you're going to do somethingone else pal I'm making the decisions Marie suier and James McKenzie both pointed out that what you define to be best is actually kind of vague I mean you might judge that one thing is best relative to one goal and something else is best relative to another goal so what's going on there that's actually a really good point I guess the ostensible response is that what you judge to be best is the thing that you judge you have the most reason to do but that takes us into the philosophy of reasons and how they work which would actually make a very good episode for another time so thank you for that calb Harman that is exactly what Plato said well done you were paying attention that's all we've got time for this week thank you very much for watching and I will see see you in the next episode don't forget to I am the real Ollie I am shut up I am the real Ollie piss off