Jacques Derrida s deconstruction and Jurgen Habermas discourse ethics are two major philosophical perspectives or modes of investigation in contemporary philosophy. Both of them shares commun philosophical problems even if they are thought in radical different ways. This work s aim is to follow the confrontation between the works of Habermas and Derrida when it was starred by the authors and to produce philosophical confrontations of these works when it haven t effectively happened. Three major problematic fields will be explored by this thesis: the question of language and communication, the problem of the limits of philosophy (and its relation with literature and neighboor fields) and the question of the political heritage of modernity: reason or rationalization of the world and cosmopolitanism as the rational possibility of the universal in politics. Beyond these specific philosophical orientations, this work s aim is to offer some intellectual discussion to contribute to the philosophical field itself. In this sense, the research strategy developed here was to operate with two axes as starting points. First, my concern was to follow the guideline of ethics in the derridian and habermasian thought, trying to find in their works this theme s conditions of development, not necessarily embossed since its early philosophical developments. Derrida never denied that deconstruction is an ethical question in itself. Since his early formulations on the concept of trace, the question of the other occupied the central scene of deconstruction s thought. In other hand, the communicative action theory since its origins tried to think an alternative to the instrumental rationality as the possibility to recover what Habermas called early in his work: the emancipatory interest of the Enlightenment based in the communication supported by rules able to secure a free of violence and external pressure discussion. Habermas will recognize in the structure of this free of violence communication an universalist and ethical principle capable to bring together the speakers in a consensus, even if it is not mandatory that they share strong moral values. As a second problematical axe, arises the problem of modernity. Habermas makes communication oriented by validity claims derive from the modern process of rationalization - conceptually oriented by the reinterpretation of Hegel and Weber -, wich ensures the possible soil for the discourse ethics. This work s themes will operate over the relation between ethics and modernity or the trace of modernity wich marks the ethics (Habermas) or the trace of the ethics wich works over the concept of modernity in an Enlightenment to come (Derrida).