Theory and History of Ontology

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  • "History Logic" and "Bibliographia" are my other websites. "Table of Contents" gives the list of the pages, for other indexes see the "Sitemap". "Modern Ontologists" contains a table with links to the pages on the most important philosophers of the 19th and 20th centuries who have written on ontology. The "Search" function can be used to find a particular author or subject.


Entia rationis. History of the Theories of Non-Existent Objects


"The totality of what exists, including what has existed and will exist, is infinitely small in comparison with the totality of the objects of knowledge. This fact easily goes unnoticed, probably because the lively interest in reality which is part of our nature tends to favor that exaggeration which finds the non-real a mere nothing (...) or, more precisely, which finds the non-real to be something for which science has no application or at least no application of any worth."

Alexius Meinong - On the Theory of Objects - in: Roderick M. Chisholm (editor) - Realism and the Background of Phenomenology - Translated by I. Levi, D. B. Terrell, R. M. Chisholm - Glencoe, Ill: Free Press. pp. 76-117 (1960) p. 79.

"Whether or not there are non-existent objects seems to be one of the more mysterious and speculative issues in ontology. To affirm that there are non-existent objects is to affirm that reality consists of two kinds of things, the existing and the non-existing. The existing contains all of what is in our space-time world, plus all abstract objects, if there are any. Most people, it seems fair to say, would think that this is all there is. For the only real question in ontology can be what kinds of existing things there are. However followers of Meinong maintain that this isn't all there is. There is also another kind of things, those that do not exist. And to say this, the Meinongians continue, is to accept that reality is divided into two basic kind of things, the existing and the non-existing. Whether or not reality contains two basic categories of things, existing and non-existing, or only one, existing, is what the debate about non-existent objects is all about. And as such it seems to be the most speculative of the debates in ontology.

Thomas Hofweber - Quantification and non-existent objects - in: Anthony Everett and Thomas Hofweber (eds.) - Empty names, fiction and the puzzles of non-existence- Stanford: CSLI Publications, 2000, p. 249

"In this book I consider the ancient problem of nonbeing, the problem whether there are non-existent objects. Holding that there are seems to imply the contradiction that there exist things that do not exist. On the other hand, in common parlance we very often speak of things that do not exist. Sherlock Holmes does not exist, he is a fictional character. Pegasus is mythical and hence non-existent. Phlogiston has turned out not to exist. Extinct species no longer exist, future items do not exist yet, there are all sorts of possible things that do not exist. Atheists certainly believe that God does not exist. So we employ the notion of nonexistence widely and quite comfortably. Furthermore, non-existent things seem to have properties: Sherlock Holmes is a detective who plays the violin, he is not a banker; Pegasus is a winged horse, not a flying fish. The appearance is that ordinary discourse is committed to items that are some- how there and have properties, and yet are said not to exist. Does common language then assume contradictory entities? Surely there cannot be such things. But if not, what are we talking about in these cases? This is a tangle indeed; my purpose in this book is to sort through the strands wound together here and to use the resulting clarifications to deal with various philosophical issues."

Charles Crittenden - Unreality: the Metaphysics of Fictional Objects - Ithaca: Cornell University Press, 1991, p. 1

"I think that it would be useful to have a detailed study of the history of non-existent objects, but I am sure that this would be the culmination of a life's work if done well. (...) One must be aware of the dangers which await one who enters the treacherous waters between the Scylla of ignorance of the history of philosophy and the Charybdis of simplicistic formulations of that history."

Kenneth J. Perszyk - Non-existent Objects: Meinong and contemporary philosophy - Dordrecht: Kluwer, 1993, p. 68

"Non-existence theories first arose in the early Stoa. A doctrine of non-things, detailed in Chrysippus' discussion of the four Stoic categories, might well be traced back to Zeno. Among these non-existent 'things' were immaterial grammatical causes (lekta) which acted semantically as the verification principles of existential propositions (axiomata). In his critique of Aristotle in the in the [Logica] Ingredientibus, Abaelard arrived at a similar theory in his discussion of propositional dicta.

Infrequent classical references to the Stoic theory, coupled with misinterpretations, point to the pervasive influence of the Aristotelian association of the categories with things."

Daniel F. Blackwell - Non-ontological constructs : the effects of Abaelard's logical and ethical theories on his theology: a study in meaning and verification - Bern: Peter Lang, 1988,p. 80;


"The Stoics want to place above this [the existent] yet another, more primary genus... Some Stoics consider 'something' the first genus, and I shall add the reason why they do. In nature, they say, some things exist, some do not exist. But nature includes even those which do not exist -- things which enter the mind, such as Centaurs, giants, and whatever else falsely formed by thought takes on some image despite lacking substance."

Sextus Empiricus, Against the professors 10.218 (SVF 2.331, part)

"They [the Stoics] say that of something some are bodies, others incorporeals, and they list four species of incorporeals -- sayable (lekton), void, place and time."

Simplicius On Aristotle's Categories 66,32-67,2 (SVF 2.369, part)

"The Stoics see fit to reduce the number of the primary genera, and others they take over with minor changes. For the make their division a fourfold one, into substrates, the qualified, the disposed, and the relatively disposed."

"In Stoic usage, just as in Epicurean, the ordinary Greek verb 'to be' (einai) can with relative safety be rendered 'exist', despite its vexed earlier history in Greek philosophy. This translation is further justified by some of the Stoic conceptual distinction discussed below.


The Stoics avoid the common Platonist assumption (...) that to be something is already to exist. To be something is rather, it seems, to be a proper subject of thought and discourse. Most such things do also exist, in that they are bodies. But an incorporeal like a time, or a fictional object like a Centaur, does not. Since, however, expressions like 'Centaur' and 'today' are taken to name something, even though that something has no actual or independent existence (independent, that is, of the world's motion in the case of time, or of someone's mental image, in the case of the Centaur), Although they deny themselves the term 'exist' for such cases, the Stoics have recourse to the broader term under which it falls, 'subsist' (huphistasthai) This latter term, in its Stoic usage, seems to capture the mode of being that Meinong called bestehen and Russell rendered by 'subsist' (in his 1904 articles on Meinong in Mind 13 [reprinted in: Douglas Lackey (ed.) - Essays in Analysis - pp. 21-93]. For Meinong, similarity or Pegasus, for instance, subsist but does not exist. With existing things, however, they share the fact that they have a character (Sosein), just as in Stoicism both a real horse and a Centaur are 'something'. We could render the Stoic distinction between 'exist' and 'subsist' by saying 'There's such a thing as a rainbow, and such a character as Mickey Mouse, but the don't actually exist'.

'Something' is the highest genus, including as it does incorporeals and fictional entities as well as bodies (see stemma above)."

Seneca, Letters 58.13-15 (SVF 2.332, part) - (SVF= Hans von Arnim - Stoicorum Veterum Fragmenta - Lipsia 1903-1905)

From: A. A. Long & D. N. Sedley - The Hellenistic philosophers - Cambridge: Cambridge University Press, 1990, pp. 163-164.


Scholastic Divisions of Being

(From: Bernard Wuellner, Dictionary of Scholastic Philosophy, Milwaukee: Bruce Publishing Company, 1956 p. 14)