Where does substance collide?

A form of matter that has a definite, constant composition and a characteristic set of properties, such as a single pure element or a single pure compound, as distinct from a mixture of two or more of these. The IUPAC Compendium of Chemical Terminology (the Gold Book) fixes this usage, treating a chemical substance as matter of a fixed makeup that cannot be separated into components by physical means. The referent here is a material sample defined by what it is made of and how it behaves, identified in a laboratory, and it has nothing to do with what a philosopher says underlies a thing's properties, what a statute lists as a regulated drug, or what a linguist calls the raw material of a language.[1]

Unit

One pure element or compound of constant composition

Recovery means

Not applicable

Measured by

Identified by constant melting and boiling points, density, and spectra, and shown to be inseparable by physical means

The basic kind of thing that exists in its own right and underlies or carries properties, rather than existing only as a property of something else: a horse or a person is a substance, while its color or its height is not. The category runs from Aristotle's ousia, through Descartes and Spinoza, to modern treatments such as Lowe's 2006 The Four-Category Ontology, which defends substances as independent particulars that bear attributes. The referent is an ontological category, a role a thing plays in a theory of what there is, and it is not a laboratory sample of matter, a drug named in a statute, or the raw material a linguist opposes to form.[2]

Unit

One independent particular that bears properties

Recovery means

Not applicable

Measured by

Argued for by its role in ontology: what can exist on its own and support properties, versus what depends on a bearer

A drug or chemical whose manufacture, possession, distribution, and use are restricted by statute because of its potential for abuse and its accepted medical use. In the United States the Controlled Substances Act of 1970 sorts such substances into five schedules, from those banned outright to those available by prescription, and comparable regimes exist under the United Nations drug conventions. The referent is a legal classification attached to a compound by legislation and regulation, and whether a compound counts turns on the law, not on chemistry alone: it is a different construct from matter of fixed composition, from the metaphysician's bearer of properties, or from a linguist's raw material.[3]

Unit

One drug or chemical placed on a legal schedule

Recovery means

Not applicable

Measured by

Determined by statutory schedules and regulatory listing, based on abuse potential and accepted medical use

The unformed raw material of a language, the continuous stuff of sound or of meaning, on which the abstract system of form imposes its distinctions. In Hjelmslev's 1961 Prolegomena to a Theory of Language every plane of a language, expression and content alike, has a substance and a form, and it is the form that structures the otherwise shapeless substance into a system. The referent is a theoretical layer in a model of language, the material that form organizes, and it is unrelated to a pure chemical sample, to the metaphysician's independent bearer, or to a drug named in a statute.[4]

Unit

One plane's raw material, of expression or of content

Recovery means

Not applicable

Measured by

Distinguished from form in analysis by isolating the material continuum that the linguistic system carves up