Since the origins of Western philosophy, personal identity dealt with the rise of many philosophical questions about ourselves by virtue of our being living things, conscious beings, material objects, etc. One of these questions is, what is the relationship between survival and identity? As a start to explain the popular ideas of this question, we will go back to the ideas of John Locke. Locke’s notion of man refers to its physical form or shape. A man is an animal with a certain organized form. His notion of person, or self, is that it is is a thinking intelligent being with reasoning and reflection, that can consider itself as itself, the same thinking thing in different times and places. Thus, “person” and “human” are distinct concepts, referring to different entities. Personal identity is, “The sameness of a rational being.” The self and personal identity reflect each other’s change. Also, consciousness always accompanies thinking. Locke’s notion of personal identity is explained through the memory theory. His criterion of the synchronic identity is that simultaneous experiences can belong to the same person when one experience (perception) is reflecting awareness of the other(s). His standard of diachronic identity is that if a person from the future is the same as a person in the present and is able to have consciousness (memory) of the experiences of the person in the present and/or the present individual reflects awareness of his/her experiences. Memory of the experiences of the prior person-stage is both necessary and sufficient for being identical with that person-stage. He says that if one does not remember some experience then, he/she did not have it. This concludes that memory is both a necessary and sufficient condition of self, and therein, personal identity. Later in time, Bishop Joseph Butler aimes to criticize Locke’s memory theory, especially for the idea that the self might be something other than a substance. Butler agrees that memory reveals past stages of one’s self. However, he argues that consciousness of that past experience is not what makes the individual that person; rather, consciousness of personal identity, presupposes personal identity. According to Locke’s view, the unity-relation for person-stages is consciousness (memory). On the other hand, Butler argues that the unity-relation is either in place or not, regardless of what is remembered. Thus, Locke’s idea is circular it is the collection of essential properties of the self that is the special substance, not only the memories that one holds. Nonetheless, Butler expresses the thought that identity is strictly tied to one’s patterns of concern/anticipation. He concludes that anticipation is identified with only strict identity, that all which is true of A is true of B. This shows that Locke denies strict identity thus, denying the justification of identity. Next on the list is Thomas Reid, who proposes a sound argument against the memory theorists which is usually referred to as the”Brave Officer Paradox.” Reid states, “Suppose a brave officer to have been flogged when a boy at school for robbing an orchard, to have taken a standard from the enemy in his first campaign, and to have been made a general in advanced life; suppose, also, which must be admitted to be possible, that, when he took the standard, he was conscious of his having been flogged at school, and that, when made a general, he was conscious of his taking the standard but had absolutely lost consciousness of the flogging” (Reid). Locke’s view implies that one can be identical and not identical with a person who executed a particular action. This objection invokes the principle of transitivity which states that if A is equal to B and B is equal to C then, A is equal to C, applying it to identity. He suggests that by Locke’s theory, the officer is the same as the person who took the standard if there is memory of taking the standard, and he who took the standard is the same as the one flogged if there is memory of having been flogged. Reid demonstrates that is relationship of sharing personal identity is possible with the transitivity theory. The fact that this was concluded using Locke’s own theory, shows that Locke’s idea of denying this identity is ignoring the transitivity property and is therefore, incorrect. There are many generally accepted features of identity. To start, the Circularity Objection states that with the memory theory, it claims if S remembers doing A, S is identical with the someone who did E. So, in order for the fact that S remembers doing A is true, it should be the same as “S remembers herself doing A.” Finally, memory entails the idea of self-identity thus, it is circular to define self-identity in terms of memory that includes the notion of self-identity. The Privileged Access to the Past is knowledge of the past that can be acquired by present data like diaries, photographs, etc. however, not being memory. Next, the Previous Awareness Condition entails that the rememberer of an event should have observed or experienced the event. Following that, the rememberer of doing an action should have done the action. Immunity to Misidentification is an important class of first person memory that claims is immune to “error through misidentification.” This is because not all consciousness is accessible from a third person view, but can be accessed by the individual itself (first-person). Nonetheless, the Previous Awareness Condition and Immunity to Misidentification is necessary for a true memory claim. The Shoemaker’s Strategy is used to break the connection between “S remembers doing A” and “S remembers herself doing A” by introducing a notion of quasi-memory that is just the notion of memory stripped of the identity-presupposing element in the latter memory chain. Finally, the Shoemaker’s formulation of Personal Identity condition is that even with the possibility of branching causal connections such as memory through hypnotism, we can still say that if a mental state of a person P at t2 and a mental state (experiences/actions) of a person Q at t1 is causally connected then, they are identical, unless there is branching during the interval. In “Personal Identity and Individuation”, Bernard Williams puts forward his Reduplication Problem. Most notably, his argument led the discussion about whether identity is a matter in survival through time. Williams imagines the case of a man called Charles who turns up in the twenties century claiming to be Guy Fawkes. All the events he claims to have witnessed and all the actions he claims to have done point unanimously to the life of some person in the past, Guy Fawkes. Every Charles’ memory claim that can be checked corresponds to the pattern of Fawkes’ life as known by historians. Others that cannot be checked are plausible. Every evidence we can have supports reincarnation. Then do we have to believe the reincarnation? Williams’ answer is “No” because if the reincarnation happened to Charles, it could also happen simultaneously to another, for example his brother Robert. Then we have two equally good candidates for identity with Guy Fawkes. But two persons cannot be one person. Therefore, neither of them could be Guy Fawkes. Charles is not Guy Fawkes. After the many thought experiments, Williams came up with the only x and y principle. This states that Whether a later individual y is identical with an earlier individual x depends only on facts about x and y and the relationship between them. That is, it cannot depend on facts about any individual other than x or y. Williams also talks about the Best Candidate Idea for Personal Identity which states that whether a later individual y is identical with earlier individual x can depend on whether there is any better candidate than y around at the later time for identity with x. This idea means that personal identity is determined on the existence of other things, better candidates. In other words, the personal identity is not determined exclusively in virtue of the intrinsic properties of two objects in question. The best candidate idea is inconsistent with the only x and y principle. Derek Parfit proposes that we separate the notions of identity and survival. Parfit states that it makes sense to think of someone surviving after having his or her brain transplanted into a new body because “the resulting person has the original person’s character and memories.” David Wiggins imagines a case where one person’s brain is split in two and each hemisphere is transplanted into a new body. Parfit thinks that in this case we must say that the person survives as two persons. Thus, in order to avoid contradictions, Parfit separates survival and identity since the two resulting persons are clearly not identical. Parfit then redefines memory and other psychological relationships such that one need not be the same person as the one who originally experienced the thing remembered. This implies that survival is not transitive. If X remembers most of Y’s life and Y remembers most of Z’s life, X will not necessarily remember most of Z’s life. For Z to survive as X, X must have direct memories of Z’s life. However, these conditions of survival imply that survival is a relation of degree. For example, severe brain damage proves that Parfit needs to either say the degree the psychological connectedness must obtain in order for it to count as survival, or his theory predicts that one can survive as another person without dying. In conclusion, we do not judge survival on the basis of connectedness of psychological states because in a scenario between A and B, B can die before A. So, what matters in survival? Parfit answers by saying that it is mental connectedness and continuity between the present mental state and future mental states. Meanwhile, the common sense answer is that it is identity between one’s self and his/her future. However, David Lewis defends the point that both answers are correct. A person as a temporal continuant is an aggregate of her temporal parts, person stages. With this in mind, two relations can be considered: (1) a relationship between a person as a continuant and its person-stages; (2) a relationship between the person-stages. Next, he introduces the R-relation which is a relation of mental continuity and connectedness between person stages. The I-relation is a relation between person stages of a single continuant person. Any stages of one and the same person are I-related to one another. He says that necessarily, two stages are R-related just in case they are I-related. Parfit replies saying that the I-relation is irrelevant however, in the case we’d have to say that when two people share a stage, one of them can have what matters in survival at that time and the other one not. But when two people share a stage, they are exactly alike in many ways atthat time, and in particular exactly alike in their psychological states at that time. In conclusion, they can’t differ in whether they have what matters in survival. From the views among these philosophers and metaphysicians, Williams and Lewis seems to be ahead the most in terms of the relationship between survival and identity. The reduplication problem brings a case to the table that can be compared not only for reincarnation, but for the whole problem of the cases of the memory theory or any psychological continuity criterion of personal identity. Although thinkers like Parfit and Locke were close and brought interesting questions/cases to the table, Lewis criticized these ideas by showing the relationship between mental continuity/connectedness to matter just as much with identity when it comes to what matters for survival. I would agree with these thoughts better than the others because identity and survival are both needed in human existence, two R-related stages are just as much I-related.