these two senses of the verb 'to mean', and does not offer an explicit theory that separates the ideas they're used to express. Instead, he relies on five differences in ordinary language usage to show that we use the word in (at least) two different ways. Intention-based semantics For the rest of "Meaning", and in his discussions of meaning in "Logic and Conversation", Grice deals exclusively with non-natural meaning. His overall approach to the study of non-natural meaning later came to be called "intention-based semantics" because it attempts to explain non-natural meaning based on the idea of a speakers' intentions. To do this, Grice distinguishes two kinds of non-natural meaning: Utterer's meaning: What a speaker means by an utterance. (Grice wouldn't introduce this label until "Logic and Conversation." The more common label in contemporary work is "speaker meaning", though Grice didn't use that term.) Timeless meaning: The kind of meaning that can be possessed by a type of utterance, such as a word or a sentence. (This is often called "conventional meaning", although Grice didn't call it that.) The two steps in intention-based semantics are (1) to define utterer's meaning in terms of speakers' overt audience-directed intentions, and then (2) to define timeless meaning in terms of utterer's meaning. The net effect is to define all linguistic notions of meaning in purely mental terms, and to thus shed psychological light on the semantic realm. Grice tries to accomplish the first step by means of the following definition: "A meantNN something by x" is roughly equivalent to "A uttered x with the intention of inducing a belief by means of the recognition of this intention". (In this definition, 'A' is a variable ranging over speakers and 'x' is a variable ranging over utterances.) Grice generalises this definition of speaker meaning later in 'Meaning' so that it applies to commands and questions, which, he argues, differ from assertions in that the speaker intends to induce an intention rather than a belief. Grice's initial definition was controversial, and seemingly gives rise to a variety of counterexamples, and so later adherents of intention-based semantics—including Grice himself, Stephen Schiffer, Jonathan Bennett, Dan Sperber and Deirdre Wilson, and Stephen Neale—have attempted to improve on it in various ways while keeping the basic idea intact. Grice next turns to the second step in his program: explaining the notion of timeless meaning in terms of the notion of