The theories of common morality start with the idea of a set of moral rules generally accepted, albeit at a pre-theoretical level. The common morality is also assumed to be universal, trans-historical, implicit and, of course, systematic. Some scholars prefer to speak about a common set of universally recognized values and understand them as a kind of common language which makes communication possible beyond the cultural boundaries. This paper give firstly a brief account of these ideas. My aim is to display some of the benefits and the limits of this concept in one particular circumstance, namely the moral dilemmas. I will discuss three versions of ethics fundamentals at a pre-theoretical level (1, 2, and 4) and I will mention several objections to these projects (3, 5). I will present an example of common morality at work, because, according to some authors, it serves as grounds for decisions in the medical practice (6). Finally, I will show what common morality can provide when facing the moral dilemmas (7, 8). This result will lead us to a less obvious, though crucial, aspect of moral reasoning: its hermeneutical work (9). I believe this feature proves the openess, fallible, provisional, and perfectible nature of the solutions we can give to the moral dilemmas.