Knowledge derived from familiarity
Bertrand Russell makes a distinction between two different kinds of knowledge: knowledge by acquaintance and knowledge by description. Whereas knowledge by description is something like ordinary propositional knowledge (e.g. "I know that snow is white"), knowledge by acquaintance is familiarity with a person, place, or thing, typically obtained through perceptual experience (e.g. "I know Sam", "I know the city of Bogotá", or "I know Russell's Problems of Philosophy").[1] According to Bertrand Russell's classic account of acquaintance knowledge, acquaintance is a direct causal interaction between a person and some object that the person is perceiving.