We understand ourselves in the first person, and because of this we address our remarks, actions and emotions not to the bodies of other people but to the words and looks that originate on the subjective horizon where they alone can stand.
This mysterious fact is reflected at every level in our language, and is at the root of many paradoxes. When I talk about myself in the first person, I utter propositions that I assert on no basis and about which, in a vast number of cases, I cannot be wrong. But I can be wholly mistaken about this human being who is doing the speaking. So how can I be sure that I am talking about that very human being? How do I know, for example, that I am Roger Scruton and not David Cameron suffering from delusions of grandeur?
To cut the story short: By speaking in the first person we can make statements about ourselves, answer questions, and engage in reasoning and advice in ways that bypass all the normal methods of discovery. As a result, we can participate in dialogues founded on the assurance that, when you and I both speak sincerely, what we say is trustworthy: We are “speaking our minds.” This is the heart of the I-You encounter.
Hence as persons we inhabit a life-world that is not reducible to the world of nature, any more than the life in a painting is reducible to the lines and pigments from which it is composed. If that is true, then there is something left for philosophy to do, by way of making sense of the human condition. Philosophy has the task of describing the world in which we live — not the world as science describes it, but the world as it is represented in our mutual dealings, a world organized by language, in which we meet one another I to I.