(n.) A preliminary remark or observation; an introductory discourse prefixed to a book or treatise.

a priori knowledge abbreviation abbreviature abrege abridgment abstract anticipation article brief buddhi capsule causerie clairvoyance compend condensation condensed version conspectus descant digest direct apprehension discourse discussion disquisition dissertation draft epitome essay etude examination excursus exposition feature first approach head homily immediate cognition insight inspiration introductory study intuition intuitionism intuitive reason intuitiveness intuitivism knowledge without thought lucubration memoir monograph morceau note outline overview pandect paper paragraph piece precis precognition preliminary study prolegomenon research paper review rubric satori screed second sight second-sightedness shortened version sixth sense skeleton sketch special article study subconscious knowledge subconscious perception survey syllabus synopsis term paper theme thesis thumbnail sketch topical outline tract tractate treatise treatment unmediated perception