structural:scholar_edition, quality:correction, structural:reformatting
Non-propositional

Non-propositional knowledge is knowledge in which no essential relation to a proposition is involved. The two most well-known forms are knowledge-how (know-how or procedural knowledge) and knowledge by acquaintance. To possess knowledge-how means to have some form of practical ability, skill, or competence, like knowing how to ride a bicycle or knowing how to swim. Some of the abilities responsible for knowledge-how involve forms of knowledge-that, as in knowing how to prove a mathematical theorem, but this is not generally the case. Some types of knowledge-how do not require a highly developed mind, in contrast to propositional knowledge, and are more common in the animal kingdom. For example, an ant knows how to walk even though it presumably lacks a mind sufficiently developed to represent the corresponding proposition.

Knowledge by acquaintance is familiarity with something that results from direct experiential contact. The object of knowledge can be a person, a thing, or a place. For example, by eating chocolate, one becomes acquainted with the taste of chocolate, and visiting Lake Taupō leads to the formation of knowledge by acquaintance of Lake Taupō. In these cases, the person forms non-inferential knowledge based on first-hand experience without necessarily acquiring factual information about the object. By contrast, it is also possible to indirectly learn a lot of propositional knowledge about chocolate or Lake Taupō by reading books without having the direct experiential contact required for knowledge by acquaintance. The concept of knowledge by acquaintance was first introduced by Bertrand Russell. He holds that knowledge by acquaintance is more basic than propositional knowledge since to understand a proposition, one has to be acquainted with its constituents.