Principle suggested by the contemporary American philosopher Gilbert Harman in response to Gettier examples in the theory of knowledge. In such cases a person is justified in believing something true, but does not know it, because the truth is somehow incorrectly connected with their evidence. Harman suggested that the incorrect connection lies in the fact that the person’s chain of reasoning passes through a false step. However, it has been argued that similar cases can be constructed in which there is no false step.