Background and Study Aim: In history, different purposes lead to learning how to fight. Traditionally, there were and are martial arts based on rituals and intuition. Fighting was institutionalised in combat sports. Then scientific, or quasi-scientific approach to self-defence was more and more highlighted. Together with the evolution of thinking, the way of understanding the process of learning self-defence changed. A. Comte stated three general stages of the knowledge as fictitious, abstract and scientific. The purpose of this theoretical study is knowledge about approaches in self-defence. Material and Methods: Theoretical methods were used for analysis in this article. The statements in this paper are based on analogy based on three general stages of the knowledge by A. Comte. For analysis of self-defence systems, induction and deduction were used to categorise them systematically. Comparison of different approaches in self-defence is used for the mixed assessments of three elements of self-defence learning as the student, the instructor, and the system. Results: This article describes three fundamental approaches to self-defence training. We come out from the basic paradigm of fighting as a natural process. At the lowest level of evolution is self-defence training based on belief. Belief is irrational and without direct relation to reality. The second level of self-defence training based on experience is close to reality and grows out from reality. At the highest level of evolution is self-defence training based on evidence. Currently, there is not enough scientific information to achieve this level. At the same time, any self-defence system should be based on the evidence, the instructor should be well educated and experienced, and student should be motivated and should believe in the system and the instructor. Conclusions: This approach calls for close co-operation between security forces and the academic community. On the other hand, there is need to re-define self-defence, self-protection, and personal safety, as the way of physical defence from the attack, the way of protecting the body in an unexpected situation, and the way of being in safe both physically and mentally.