AbstractHistorical thinking is the type of thinking that learns lessons from past historical events and applies them to the modern world. In order to apply lessons, the future situation after the lessons have been applied should be inferred. The future situation has been affected by the causal relationships between people and between properties of the people. In this study, an “if thinking” learning method is introduced so as to understand such causal relationships. In this approach, the change of one historical element is given and its influence on other elements is asked as a question. To answer the question, consider various causal relationships between people and their properties must be considered. In this study, we have also developed a system for presenting “if” situations and judging learners’ answers automatically. The experimental result showed that our system was effective in acquiring causal relationships.