A tacit assumption or implicit assumption is an assumption that underlies a logical argument, course of action, decision, or judgment that is not explicitly voiced nor necessarily understood by the decision maker or judge. These assumptions may be made based on personal life experiences, and are not consciously apparent in the decision making environment. These assumptions can be the source of apparent paradoxes, misunderstandings and resistance to change in human organizational behavior. See also Assumption-based planning Consensus reality Hidden curriculum Implicit attitude Implicit cognition Implicit leadership theory Implicit memory Implied consent Leading question Premise Presupposition Shattered assumptions theory Subreption Tacit knowledge Unsaid Unspoken rule Further reading Edgar H. Schein, Organizational Culture and Leadership, Jossey-Bass, 2004, Logic Ignorance ja:暗黙の了解