This paper formulates in the first part some requirements for a certain sort of computational argumentation systems, namely those which are designed for a very specific purpose: to motivate reflection on one's own thinking, and to induce cognitive change. This function of argumentation systems is important for argument-based conflict negotiations, deliberation processes, intercultural communication, text analysis, and learning through argument visualization. In all these situations success is only possible when people are able to change their mind, learn something, or start to reframe well-established ways of perceiving and interpreting things. Based on these requirements, I defend and explain in the second part my decision to use for Logical Argument Mapping—a method specifically designed for supporting reflective argumentation—only argument schemes that are deductively valid.