The article concerns a subject of legal dialogue. At first, a definition of discussion is explained. Then a rational discussion is described the aim of which is to strive the truth. Afterwards, a rhetorical discussion is defined whose the main purpose is to win a dispute. These two types of discussion are compared with the legal dialogue both the scientific and the practical one. This text points out the main features of the rational and rhetorical discussion. It pays attention on some differences as well. The issue of disloyal eristic tricks is also marked with an assessment of their using. In conclusion, the assessment of both types of discussion and their usefulness in scientific and practical discourse were indicated.Artykuł dotyczy pro...