Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The noumenon is a posited object or event as it is in itself, independent of the senses. It classically refers to an object of human inquiry, understanding or cognition. As a concept it has much in common with objectivity. That which is tangible but not perceivable, the reflection of phenomenon. The term is generally used in contrast with, or in relation to "phenomenon," which refers to appearances, or objects of the senses. A phenomenon can be an exceptional, unusual, or abnormal thing or event, but it must be perceptible through the senses; A noumenon cannot be the actual object that emits the phenomenon in question. Noumena are objects or events known only to the imagination - independent of the senses.