Substance & Property

1. Stanford on Substance

PDF of Stanford article. It’s a really, really well-written article, outstanding even for Stanford, which is almost uniformly great as it is. The author is Howard Robinson.

  • There is an ordinary concept in play when philosophers discuss ‘substance’, and this, as we shall see, is the concept of object, or thing when this is contrasted with properties or events.
  • The philosophical term ‘substance’ corresponds to the Greek ousia, which means ‘being’, transmitted via the Latin substantia, which means ‘something that stands under or grounds things’.
  • According to the generic sense, therefore, the substances in a given philosophical system are those things that, according to the system, are the foundational or fundamental entities of reality. Thus, for an atomist, atoms are the substances, for they are the basic things from which everything is constructed. In David Hume’s system, impressions and ideas are the substances, for the same reason. In a slightly different way, Forms are Plato’s substances, for everything derives its existence from Forms. In this sense of ‘substance’ any realist philosophical system acknowledges the existence of substances.
  • For Aristotle “The individual substances are the subjects of properties in the various other categories, and they can gain and lose such properties whilst themselves enduring. There is an important distinction pointed out by Aristotle between individual objects and kinds of individual objects.”
  • In the Categories, this distinction is marked by the terms ‘primary substance’ and ‘secondary substance’. Thus Fido the dog is a primary substance—an individual—but dog or doghood is the secondary substance or substantial kind
  • Essence: If one is concerned with kinds of substance, one obvious question that will arise is ‘what makes something a thing of that kind (for example, what is involved in being a dog)?’ This is the question of the essence of substantial kinds. 
  • if one is concerned with individuals, the parallel question is ‘what makes something that particular individual of a given kind (for example, what is involved in a dog’s being and remaining Fido)?’ This is the question of individual essences and of identity over time. Aristotle was mainly, if not exclusively, concerned with questions of the first kind, but, as we shall see in section 2.5.2 and section 3, the latter question assumed a prominence later.
  • It seems, in summary, that there are at least six overlapping ideas that contribute to the philosophical concept of substance. Substances are typified as: 1) being ontologically basic—substances are the things from which everything else is made or by which it is metaphysically sustained; 2) being, at least compared to other things, relatively independent and durable, and, perhaps, absolutely so; 3) being the paradigm subjects of predication and bearers of properties; 4) being, at least for the more ordinary kinds of substance, the subjects of change; 5) being typified by those things we normally classify as objects, or kinds of objects; 6) being typified by kinds of stuff.

2. Stanford Encyclopedia on accidental and essential properties.

PDF of Stanford article

  • “A modal characterization of the distinction between essential and accidental properties is taken for granted in nearly all work in analytic metaphysics in the latter half of the 20th century. Advocates of the modal characterization have included Ruth Barcan Marcus (1967) and Saul Kripke (1972/1980), among others.”
  • “an essential property of an object is a property that it must have, while an accidental property of an object is one that it happens to have but that it could lack. Let’s call this the basic modal characterization, where a modal characterization of a notion is one that explains the notion in terms of necessity/possibility.”
  • Essentialism in general may be characterized as the doctrine that (at least some) objects have (at least some) essential properties.”
  • According to the basic modal characterization of the distinction between essential and accidental properties, which is the characterization given at the outset
    • P is an essential property of an object o just in case it is necessary that o has P, whereas P is an accidental property of an object o just in case o has P but it is possible that o lacks P.
    • Putting this into the language of possible worlds that philosophers often adopt, P is an essential property of an object o just in case o has P in all possible worlds, whereas P is an accidental property of an object o just in case o has P but there is a possible world in which o lacks P.
  • The modal characterization of an essential property of an object as a property that an object must possess fits well with (at least one aspect of) our everyday understanding of the notion of essentiality, which often seems simply to be the notion of necessity. To say that something is essential for something else is typically just to say that the first is necessary for the second.