To outline the fundamental features of the human person, to highlight his dignity and absolute value, to point out his existential task, the key to his historical and eternal fulfillment, to approach that philosophical dimension that confers on others the ultimate meaning, to trace the origins of man and to look ahead, trying to discover a perspective of hope... is a timely and, at the same time, challenging task. One could repeat what Khalil Gibran wrote: "Only once have I been struck dumb. It was when a man asked me: Who are you?". However, we have to insist on trying to answer that question, getting closer and closer to "that great unknown", the human being of flesh and blood. Aristotle already said: "it is unworthy of man not to continue seeking a knowledge to which it is possible to aspire".The themes of this work are treated in two parts, the first is a brief introduction to philosophy and the second deals mainly with the theory of knowledge, method, science and also some questions related to space-time, matter, the universe, life, the human being, absolute being and values.