 Grammar, usually taken to consist of the rules of correct syntactic and semantic usage, becomes, in Wittgenstein’s hands, the wider—and more elusive—notion which captures the essence of language as a special rule-governed activity. This notion replaces the stricter and purer logic, which played such an essential role in the Tractatus in providing a scaffolding for language and the world. Indeed, “Essence is expressed in grammar … Grammar tells what kind of object anything is. (Theology as grammar)” (PI 371, 373). As opposed to grammar-book rules, the “rules” of grammar are not technical instructions from on-high for correct usage and are not idealized as an external system to be conformed to, independently of context. Therefore, they are not appealed to explicitly in any formulation, but are only used in cases of philosophical perplexity to clarify where language misleads us into false illusions. Thus, for example, “I can know what someone else is thinking, not what I am thinking. It is correct to say ‘I know what you are thinking,’ and wrong to say ‘I know what I am thinking.’ (A whole cloud of philosophy condensed into a drop of grammar.)” (Philosophical Investigations 1953, p.222). In this example, being sensitive to the grammatical uniqueness of first-person avowals saves us from the blunders of foundational epistemology.