We are living in an age， whose base has been shadowed. The affluence of world has been thrown into the darkness by das Gestell der Technik. Men have been uprooted， as well as the age. It has been diluted by the extension of scientism， rational calculation and hedonism so that no one can touch and feel the real world in it. In the desert of modernity， focusing on the input and output of the interest， politics has transformed into housecraft and shapes our life as economics and statistics do. It has degraded to a special administration technology. However， just the moment politics was given a birth in Greece， it was a great platform for opinions to be raised and spread， and us， the mortal human being， by being ourselves， to win virtue and honor. Modern politics subjected more to some kind of businessman’s logic， therefore， in the sense of morality and politics， we live in a dwarfed age， namely a fundamentalism of Machiavellism. How come this situation comes？ How does our great political tradition fade away？ In this paper， the author will give some tentative explanations to these questions by paying attention to the role of the Theory of Forms played in the fall of public sphere and the rise of science and technology.  In the first section，with reference to the comments on the Theory of Forms given by Hannah Arendt， the author will describe the process of the demise of the public sphere and discuss the result of it. In sectionⅡ，against the background of modern politics being reined by the paradigm of scientism and economics ，the author will take Heidegger’s thought of das Gestell der Technik and its connection to Platonism as start point and discuss the relationship between the Theory of Forms and the origin of modern politics. Moreover， since Hannah Arendt was one of the students of Heidegger， she， just like her teacher， laid the emphasis on the change the modern politics suffered with the emerging of the Theory of Forms， namely the deviation from the ancient Greek political tradition.  We will begin with the discussion about Arendt’s theory of public sphere. The core of her political theory is communicative action and public sphere. By illustrating the Aristotle’s politics in polis， she distinguished public sphere and private sphere， technology and action， thus revitalized the pragmatism of Aristotle. As far as Hannah Arendt concerned， the nature of politics could only be understood in the memory of the life experience in polis， where people could receive the real experience of politics by communicating and discussing public affairs in the public sphere. In her opinion， liberty and the meaning of life had much to do with political life. Human beings are discrepant and may think and act differently. Therefore， a communicative world must be formed. That is to say， we need to lead a political life. On the base of Arendt’s comments on the tradition of western classic politics， Arendt’s thought of action and liberty and the complexity of human action will be illustrated. The comment ′It is men， not Man who live on this earth.′ indicates that people who are equal and different come together and form a public sphere， revealing the nature of the living world. Thus， the complexity can be seen as a background against which action and public sphere exist. In this way， the unity of action and public sphere can be proved， as well as Aristotle’s famous comment on the ontology of politics that we are creatures of politics by nature． In the second section， the author will illustrate the connection between the mathematics in Platonism and the modern scientific experiment. Based on Heidegger’s thought of mathematics and the deconstruction of the essence of technology， the author will describe the path of digitization and modernization of politics. Politics has been drew into a part of metaphysics since Platonism， which results in thinking for politics， instead of thinking politics as politic. In this paper， the author will discuss the reason why politics will be shadowed during the history of metaphysics after philosophy．