|Ideal observer: An ideal observer in philosophy is a hypothetical observer who is perfectly rational, impartial, and informed. The concept is often used to discuss the nature of moral right and wrong. Other philosophers argue that this is unrealistic as we are all human beings with our own biases and limitations. See also Impartiality, Rationality, Observation, Objectivity._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments.