What is the dignity of human existence? This question, which arises not only from the natural human need to know but especially from the crises we know today, is at the heart of this work. In the answer to it, Aristotle offers, in his ethico-political theory, a conception of human life based on his discovery of nature in the Physics and Metaphysics. Human beings alone make things happen by their actions and fulfill themselves through them. This is according to nature, which is the principle of order and makes everything beautiful, and makes spring up the call for human responsibility. This work presents the human existence as a vocation to happiness. It demonstrates that through the analysis of the Aristotelian concept ‘right reason’ - orthos logos, which is the principle of human action and constitutes also the end towards which human beings must tend through education. So it is according to orthos logos that human vocation is fulfilled, and it is only the political system that has the human vocation fulfillment as its principle, through the rule of orthos logos, that promotes peace, development and happiness. Can human dignity be something else than that?