The norms of professional ethics often impose different standards of conduct on lawyers in the practicing of their profession than they would apply to an ordinary person in the same situation. The article analyzes how we can justify these differences through various ethical theories. The author describes the legal ethics as a set of legal and moral norms. He then analyzes the problem of its justification. Attention is first dedicated to various deontological approaches (eg Charles Fried, David Luban). The author analyzes their disadvantages and concludes that they must primarily emphasize the importance of moral and rational agency if they are to be credible. He evaluates utilitarian justification as appropriate. It is also this justification, combined with some pragmatic aspects, that is able to credibly justify the legal ethics. Both groups of approaches can be considered relevant and therefore it is not appropriate to exclude any of them from the professional ethics debate