Despite the difficulty in defining what constitutes personal identity, personal identity and its connection to friendship has a long history.  Aristotle’s writings on friendship viewed the highest level of friendship as a friendship in which our friend was a mirror, a mirror in which we could, to be frank, admire our own virtue. More recent work, such as Dean Cocking’s and Jeanette Kennett’s, contend that accepting aspects of our friends’ interpretation of our identity is necessary to a deep friendship (1998). While the friends in these examples play a role in forming our identity, friendship has an even deeper role to play.  Intimate friendships, I will argue, not only play a role in our identities, but are necessary for any stable and authentic notion of personal identity.     
Intimate friendship as a necessary condition for personal identity stems from a need for an appropriate authority to set the boundaries of another’s identity, and to bring into existence an objective recognition of that person’s identity.  While there are many definitions of intimacy, for the purposes of this paper, necessary to intimate friendship are mutual and robust knowledge of the individual’s engaged in the friendship, mutual love, and a desire, and ability, to be engaged with each other, which must include physical proximity at least some of the time.  As for romantic love, which is often associated with intimacy, it is neither required nor excluded in an intimate friendship.  While the proposed characteristics are not sufficient for intimate friendship, these traits put an intimate friend in the unique position of satisfying the above needs for personal identity.  
The constitution and existence of personal identity has often been contentious. However, from a phenomenological standpoint, we recognize ourselves as having certain dispositions and traits.  We view ourselves as being a separate entity from others, and this separation constitutes more than a physical space or body.  Our tendency towards personal identity exhibits itself in our refusal at times to associate with certain thoughts and actions, which emanate from us. That some thought, which we recognize as existing in our mind, is in some way not our thought, just some random idea that doesn’t cohere with how we view ourselves. Thus, my concern in this essay is not whether we take a memory, fission, or psychological approach to identity.  Instead my focus is how this identity becomes constituted, and its relationship to intimate friendship. 
	The creation of our identities can be viewed as a combination of genetic factors, social factors, and self-construction.  As for the former, it is hard to deny that some of what we like and dislike, and that some of our dispositions, are due in part of our genetics.  While my likes and dislikes are by no means the whole of my identity, they constitute part of it. In its most simple form, for example, if you are allergic to strawberries, your inability to eat them will have some bearing on your liking and interaction with this item.  Thus, even if you enjoy strawberries, and would endure breaking out in order to eat them, this action tells us something about your characteristics. 
	Genetics, however, do not play the only role in our identity.  The notion that we are, at least, in part self-constructed results from what we choose to associate or dissociate ourselves with.  Harry Frankfurt, for example, views our sense of self, in this fashion, as a series of higher order desires. Our higher order desires are those that we choose to associate with, often denying our more immediate desires (1988).  However, it is difficult to deny that the choices we associate ourselves with result from our social environment. If the social norm, for example, is one of intolerance towards sexual choice, your acceptance or rejection of this norm is a noted characteristic of your identity.  At the same time, were we to live in a society in which sexual choice was fluid and not an area of any focus we would lack anything to associate or dissociate with because it is not a focal point of choice, anymore than pepperoni or sausage is a noted choice to a non-vegetarian.  
	Beyond our inability always control the choices we are offered, our identity also relies on the actions and thoughts we are willing to take responsibility for.  Meir Dan-Cohen explains that there is often a tension between what we think we are responsible for, and what others think we are responsible for (2006).  So for example, if you have a migraine headache and are short with one of your students, you might not associate those actions as your own, but instead as the result of your migraine.  However, despite our desire to create our own boundaries, as Dan-Cohen explains, it is a process of negotiation.  
In illustrating this negotiation, Dan-Cohen examines a criminal trial.  The prosecution has an interest in drawing the boundary of responsibility widely, while the defendant has an interest in drawing the boundary of responsibility narrowly. This, however, leaves open the potential for conflict in terms identity. Individuals will not always agree on the boundaries of identity.  In which case, according to Dan-Cohen, incompatible versions of one’s identity persist with no clear determining authority.  This view coheres with the way in which we sometimes view ourselves.  Our speech acts often construe the notion that we are different persons in different environments.  Yet, in tension with this idea of multiple selves is the idea of a “real self.”  The notion of a “real self” exhibits itself in our declarations or desires to hide or expose our “real selves.”  We also communicate the belief that someone close to us knows the “real us.” This notion of a “real self” sometimes motivates the acceptance of psychopharmaceuticals.  As noted by Neil Levy in “Enhancing Authenticity,” taking certain drugs may afford us the opportunity to voluntarily identify with different ways of being that might not be possible without these drugs (2011).  Levy in his paper, posits that the voluntary identification is what constitutes the authentic self. Thus, Dan-Cohen’s understanding of identity and the theory posited by Levy create incompatible notions of identity.  Do we have multiple identities, or is there an authentic or real self? 
	The latter cases, cases where one admits multiple ways of being in relation to one’s environments, can be interpreted as expressing how different facets of our personality are environmentally dependent.  Thus, by denying a literal interpret of a different identity manifesting itself in different environments, we avoid a chasm in self-understanding.  The former case, however, where there is conflict over the boundary of identity, can be viewed as an identity in limbo, instead of multiple identities, with each identity having no more weight than the other.  The refusal of each party to accept the others’ version creates a difficulty for a theory of multiple identities.  The defendant and prosecutor do not agree that there are two different identities at play.  Instead each thinks the other is mistaken, which results from desires not necessarily concerned with the truth of an identity.  The prosecutor, in wanting to win the case, has a vested interest in drawing the defendant’s identity in a particular way, while the defendant, in wanting to avoid punishment, has an interest in rejecting the picture.  In each case, we have no reason to give either party the authority to claim that she has the true understanding of the identity in question.
	Who can stand as the authority for drawing the boundary of an identity stands at the heart of the issue. Lack of authority might lead one to think that we need world agreement in order to actualize any identity.  However, if world agreement is necessary, instead of finding consensus, we are more likely to find ourselves with a finitely large number of identities, with no one identity being any more accurate than any other, or an identity that will always be in limbo.  Neither of these possibilities is very appealing.  The former leaves us in a situation in which our own understanding of ourselves, and the understanding of our close companions, holds no more weight than someone who barely knows us, while the latter leaves us in a situation in which there is no possibility for identity at all.  
We can, however, resolve this dilemma if we can find an appropriate authority to determine where the boundary of any particular identity lies. Because we need the “buy in” of the person whose identity is in question, this authority will need the acceptance of the person whose identity is in question.  At the same time, the standards for this authority must go beyond this acceptance.  Imagine John is on trial for murder.  Because of certain circumstances, say a drug binge the night before, he denies those actions as being his own.  We can also imagine that Jane is in a similar situation.  In such a case, it benefits Jane to view John as not responsible for his actions so that she too can refuse to identity with similar actions.  
This, however, would be unsatisfactory.  Jane might know nothing else about John, setting up a situation in which the identity Jane confers upon John lacks any real connection to John, except as a way of conferring her own desired identity.  Nevertheless, this situation can be averted by requiring that an authority’s acknowledgement of an identity result from knowledge of the other person, and a commitment to recognizing this reality as being separate from her own desires.  In return, the person who accepts the other’s view of herself must have reason to believe that this person also desires to know the truth of who she is.  
Thus, our criterion for what constitutes an identity are:  Agreement between an authority and the person whose identity is in question; an authority with enough knowledge of the other to make an appropriate assessment of the identity in question; the authority’s interest must not be the result of her desires for certain characteristics, but instead the result of her desire to know the truth.  An intimate friend is the only one who would find herself in a situation in order to gain such a robust knowledge of the other person.  While others might know much about some person, only an intimate friend will be privy to thoughts, intentions, desires, associations, self-deceptions, actions, of her intimate.  Anyone who is not an intimate friend will lack the time, proximity, trust, or types of engagements in which to gain this kind of knowledge.  Additionally, the intimate friend will also be privy to her intimate’s own lack of self-knowledge, which we none of us are completely aware of.  
While it is true that the intimate has a vested interest in her friend, this interest is not an interest in creating a desired identity, but in knowing the actual identity of her intimate.  In loving her friend, she is required to love who her friend is, and not who she wants her friend to be. If she merely loves what she wants her friend to be, then her friend becomes irrelevant to the relationship. The only contribution her friend brings to the creation of how her identity is viewed is that which her friend can tolerate in terms of self-deception. This picture presents something more like imaginary friendship than intimate friendship.  
Presenting the intimate friend with such an authority does not mean that whatever the intimate views as the identity of her friend is automatically accepted as the case.  Instead we need to view the agreed upon identity as a negotiation in which each intimate takes into consideration the other’s views.  While you might not recognize some trait about yourself, you trust that your intimate has an interest in knowing who you really are, not who she wants you be.  By the same token, your intimate, in wanting to know you, must take into consideration how you view yourself, as part of her judgment will be based on what you provide as your intentions, desires, and your claims of association.  
Eventually some mutually agreed upon identity will come to pass, an agreement, which is necessary to the continuation of an intimate friendship.  A failure to agree presents a situation in which the intimate loves a person that the intimate’s friend does not acknowledge as constituting her identity.  Each intimate can then ask in what sense a mutual love can exist, as one individual does not identify with whom the love is bestowed upon, and that same individual’s love for the other does not emanate from an identity her intimate acknowledges. 
Despite the intimate friend as an authority in the negotiation of personal identity, identity will still likely conform to the social norms of boundaries for identity.  Of course, the intimate friend might reject those norms, and this is OK.  Regardless, it is important to recognize that outside of an intimate friend there is no fact of the matter regarding personal identity beyond a conjunction of the social, the genetic, and the negotiation between the intimate friends.  One’s willingness to identity with some set of characteristics bears on those characteristics.  Thus, even if there were some matter of the fact regarding the boundaries, identification outside of the boundary will have some influence on identity.  
The role of the intimate as an appropriate source of authority may be challenged on the basis of the intimates’ interest in each other.  Individuals often have desires to identify with desires, actions, etc. that are not their own, and an intimate friend could also desire these hoped for characteristics to be part of her friend’s identity. If we accept this, then personal identity becomes nothing more than a negotiation of mutual desire.  However, there are two ways in which to deal with such a possibility.  The first is to recognize how desires, even those which are unfulfilled, bear on the kind of person you are.   Perhaps you desire to be a detail oriented person, but you fail at this task in actuality. There is still a sense in which a desire to associate with some quality or other, whether or not it is fulfilled, is itself a characteristic.  Part of who we all are is constituted by what we aim for, even if we cannot achieve it.  Secondly, we generally can, if we make an effort not to be deceived, know the difference between wishing things were a certain way and having them be that way in actuality.  While this paper does not go into detail regarding what is necessary for love, that we are committed to knowing the other person beyond our desires is necessary for our love to consist something more than a projection on an imagined entity.   
The result of negotiation for a mutually acknowledged identity creates a situation in which one’s identity can be both stabilized, and yet still be dynamic.  Its stability results from an acknowledgement of a “real us,” removing our identity from limbo.  At the same time, because our intimate has a vested interest in knowing us, she has a vested interest in being fluid in her conception of us, allowing it to grow and change as we grow and change.  This fluidity is especially important in escaping Sartre’s concern surrounding a false set identity brought about by the ego.  Sartre’s concern is that once an ego is fixed in that it identifies as something or other, the person alienates herself from possibilities that a person outside of that particular role can see as a possibility. However, Adrian Mirvish, in his interpretation of Sartre’s writings on friendship as explored in “Notebooks for an ethics,” argues that an authentic friendship, which an intimate friendship can be considered, aides us in escaping this predicament (2002).  
According to Mirvish’s interpretation, we are able to escape this predicament because the relationship plays two roles.  The first role is the objectivity from a third-party sense that one friend can give to the other’s existence, and vice versa.  This is a result of Sartre’s belief that we cannot be our own foundation.  Whether or not we reject Sartre’s belief regarding the existence or our identity, at least from a phenomenal stand-point there is a sense in which we need others to acknowledge us to have a sense of being.  While discussion of this is beyond the scope of this paper for now, it helps explain our need to receive feedback and recognition from others in regards to our own being. In addition, Sartre’s concerns about a static and inauthentic ego can be captured in the frustration we often experience when others box us into a static identity where welack any room for change or growth.
The way in which this situation is avoided, according to Mirvish, is that one’s authentic friend loves one as an “independent, irreducible being in her own right” (196).  She is willing to accept that her friend can behave in unexpected ways.  Each intimate avoids imposing constraints and categories on the other, instead listening and reacting to the other in terms of the others’ “projects, aspirations, and goals” (202).
In conclusion, the importance of understanding the nature and relationship between intimate friendship and personal identity paves the way for understanding these relationships as vital to the existence of self.  Moreover, understanding of this structure elucidates the pitfalls and dangers of attempting to satisfy our needs for identity outside of something like an intimate friendship. The growing use of social networking sites for a sense of self is something that can more easily be examined against the back drop of an identity secured by an intimate friendship.   

References
Cocking, D. and Kennett, J. (1998). “Friendship and the Self,” Ethics, 108, pp. 502-527.
Dan-Cohen, M. (2006). “Socializing Harry,” in Taking ourselves seriously and getting it right, ed. Debra Satz. Stanford University Press. 

Frankfurt, H. (1988). The Importance of what we care about. Cambridge University Press.

Levy, N. (2011). “Enhancing Authenticity,” Journal of Applied Philosophy,  (DOI: 10.1111/j.1468-5930.2011.00532.x )

Mirvish, A. (2002). “Sartre on the Ego, Friendship and Conflict,” Continental Philosophy Review, 35, 185-205.