begriff; bewusstsein; bundle theory; category; category mistake; clear and distinct; concomitant variation method of; de dicto - de re; de re; dianoia; direct realism; double aspect theory; doubt - method of; idea; idealism; indubitable; ineffable; ingenium; intentionality; memory; mind-body problem; objective - subjective; objective - subjective; operationalism; opinion; time; understanding;