In political space it matters who we individually are.
Debates always involve different people. While individuals can survive and even build their own little world of things in total isolation from others, nobody can be all alone and still have a debate. Debates, so to speak, always require the plural.
“Human plurality […] has the twofold character of equality and distinction. If men were not equal, they could neither understand each other and those who came before them nor plan for the future and foresee the needs of those who will come after them. If men were not distinct, each human being distinguished from any other who is, was or will ever be, they would need neither speech nor action to make themselves understood. Signs and sounds to communicate immediate, identical needs and wants would be enough. […] In man, otherness, which he shares with everything that is, and distinctness, which he shares with everything alive, becomes uniqueness, and human plurality is the paradoxical plurality of unique beings.” (HC: 175f)
The paradoxical characteristic of “human plurality”, as Arendt calls it, is that we are all humans and in that sense equal, but still each of us is a unique individual, different from anybody who has ever lived before us, lives together with 23 us or will come after us. This uniqueness is specifically human; it distinguishes us from all other species. Human beings are unique, because they do not only physically exist as distinct individuals but because they express their distinctness in front of others through words and deeds. This articulation is what makes each of us a “somebody”. In terms of being somebody, it does not matter so much what we are – strong or weak, courageous or cowardly, intelligent or stupid -, as these are characteristics that we always have in common with others. Rather, it matters who we irreplaceably are.
“The basic error of all materialism in politics […] is to overlook the inevitability with which men disclose themselves as […] distinct and unique persons, even when they wholly concentrate upon reaching an altogether worldly, material object. To dispense with this disclosure, if indeed it could ever be done, would mean to transform men into something they are not; to deny, on the other hand, that this disclosure is real and has consequences of its own is simply unrealistic.” (HC: 183)
Since a debate, just like any other form of political action, always brings together different people who get to know each other and automatically begin to establish personal relations, it can never be entirely reduced to a material outcome. For a debate, in contrast to many other situations, it is well-nigh essential who participates. When attending a debate we are not only interested in what is being said but also in who says it. Moreover, the outcome of a debate is strongly influenced by how the participants relate to and get along with each other. Turned the other way, a debate can be interpreted as an opportunity for the participants to publically “disclose” who they are. This is not only how we get to know others, but also a way to get to know ourselves. The individual disclosure should not be mistaken for the demonstration of a trained skill that can be released at any time, let alone the presentation of a product that is already finished. Rather, it just happens. In a sense, disclosing who I am even makes me who I am. Thus only if I have the chance to show who I am can I actually be who I am. Through debates and similar opportunities people can “attain their full humanity, their full reality as men, not only because they are (as in the privacy of the household), but also because they appear” (PP: 21).