Starting with the European Renaissance and Humanism, and peaking in the Enlightenment, we have a re-evaluation of the individual. This is not, of course, merely a "reevaluation", since more than anything, it is a shift in perspective, in the way the individual, as such, is/was viewed. To keep it short, the individual gained value.
This is seen, for example, in the Reformation, which cannot be seen as necessarily "englightened" in all matters, but where it overlaps is in the sovereignty of the individual. The individual - not the Church, for example - becomes the locus for connection with god. The individual does not need the mediation of the Church, that is, to communicate with god.
The sovereignty of the individual is the focal point of modern democracies in a way. Human Rights, the Rights of Man and Citizen, "We hold these truths to be self-evident [...]" - government representatives are there to represent us and our desires, not the goals of an abstract state. This is in direct contradiction to many so-called democratic states. Let us take the example of "Bosnia" - there are several political parties, and all the powerful ones are "ethno-national" ones - the Croatian something, the Serbian something, the Bosnian something party. There are parties not defined in this way, but they have no power (let's hope that changes at some point). That is, not the interests of the individual as an individual are being represented, but the interests of the "individual" as an ethnic persona.
Of course, the individual is a fiction - let us try to examine individual identity. What does identity mean? It means unity. Singularity. It is that which can be indentified - that is, distinguished. In an ever-changing, sometimes chaotic world, the search for identity is a search for the stable. However, this is merely a construct, albeit a useful one. What is "ours" - what is part of "us"? Why our skin but not our shirt? Our skin is dead, it cannot feel. And our hair? Or, when one dies, our fingernails continue to grow, despite the fact that as an individual we are dead.
Psychologically, we talk of an identity - and those that have "multiple personalities" and "split personalities" are abnormal, freaks - sick. We see our "id", "ego" and "super-ego" as three parts of a whole - Holy Trinity of sorts. Or, the "anima" and "animus" - two distinct aspects of an identity in a sort of psychological dialectic. We are allowed to have two sides - a light side, and a dark side, but one must dominate, of course, but the point is that simplifying one's "identity" to one, two, or even three distinct, self-contained parts is a convenient fiction. Are we the same person as a child as we are as an adult - of course not. We claim, "ah, but that is growth, development, progress." That progress and growth is an illusion we use to give meaning to that change. There is no unified "indentity" that the so-called individual has - merely a myriad of aspects, each of which having a different amount of influence on the so-called individaul; many are inter-related and dependent upon others. Since individuals are all different, then no two individuals are equal.