What is the value of ontology? Can there be an absolute perspective on an ontological question, or only an open, non-final answer? What, if any, are the implications of ontological facts? This paper argues that ontology is a valuable endeavour, aiming at understanding reality better; that ontological answers are often incomplete; that knowing ontological facts may have consequences, so ontological investigations may lead to human progress.
1. Why is it worth answering ontological questions?
Ontology faces scepticism at the outset, scepticism about abstract knowledge of reality (of some portion of reality): ontology gives only knowledge from a distance (abstract), knowledge in general. It is said that it is often vague, imprecise, insensitive to some details, therefore involving mistakes, except with regards to portions of reality which are insusceptible of change (recall Russell on universals), perfectly exact, limited, ‘mathematical’.
So what is the value of ontological work about poems, works of music, paintings, art, moral values, aesthetic properties, justice, God? Since these areas matter to us, knowledge of these must be useful, but how useful is general, abstract knowledge in non-mathematical areas such as these?
What poems, works of music, paintings, art, moral values, aesthetic properties, justice, God are (ultimately) is not obvious, or simply a matter of incommensurable or, at least, incompatible descriptions. And having a better understanding of what these things are is helpful in making decisions about what is a priority to promote, protect, or do without, ignore, exclude. And seeing an area from a distance may allow for noticing features of that reality that a close approach may not show so clearly: think of the Earth as the blue planet. Only from a distance we can see the Earth as the blue planet it is.
2. ‘We-know-what’ vs. ‘we-know-not-what’
What does ontology add to our knowledge of what there is? If we knew (were aware of) all the facts about some portion of reality, there would be no need for an investigation into its nature. Ontological investigations presuppose incomplete understanding of some portion of reality and they seek to improve such understanding. We are unclear about the ontological nature of some reality we partially know and we seek to learn more about it, through observation and reflection. So in a sense ontological perspectives investigate ‘we-know-not-what’, assuming that reflection and argument, and our partial understanding, can lead to further clarity, to a better, more complete vision of the portion of reality in question.
But ontology does not simply add clarity and detail to our picture of (some portion) of the world. It also investigates and makes explicit the commitments of such picture. So it enlarges our awareness not only of the contours of the reality in question but also of its relations to other areas of reality. In this sense, ontology can be a source of genuine knowledge, of an advancement of theoretical truth.
This—the claim that ontological questions are worth pursuing because they can lead to genuine knowledge—had to be asserted because it has been questioned. Indeed, philosophers have argued that ontological disagreements are merely linguistic (over the meanings of the words used), not factual, or else that the answers to ontological questions are trivial, not substantial. But if ontology aims to investigate what there is, the nature of (some portion of) reality, then surely its results are to be worth pursuing: they cannot be merely linguistic or trivial. Let me explain why.
Even if we use the analysis of language (and concepts) to assess and investigate our knowledge of reality (for example, by making explicit what commitments our language use suggests), the focus of our investigation is beyond language, even when language is its starting point: we ought to critically evaluate our use of language, to see where there is genuine commitment to the existence of some reality or whether there is careless (or at least mostly insignificant) use which should be replaced by better language. But the focus of ontology is reality, not language, even when we use language as a necessary (although imperfect) instrument. When we are interested in saying whether, say, there are any numbers, or properties, or even God, we are asking a question about the world: we wish to know whether these are genuine constituents (or even potential makers) of reality. Our use of language may aid us in this endeavour, but its analysis is not all that there is (and it should be made with great care, to avoid creating confusion instead of progress) and it should serve the project of the investigation of reality.
Because they involve an investigation of (some portion of) reality, not simply or finally of our use of language, ontological questions are not trivial. This is because the reality that ontological questions investigate is not simple, so ontological answers always involve complex decisions—and the possibility of error.
3. Can ontology be absolute?
The very nature of reality makes an absolute ontology—one which would reveal the ‘ultimate’ nature of reality—impossible. So in a sense ontology is set up for failure: it cannot fully achieve its traditional goal. This is because reality is multifarious, multifaceted, multidimensional, so a single description of it cannot capture this diversity and natural complexity. But this should not undermine generally the project of ontology, only its most grandiose pretensions, its (arguably unreasonable) urge to give final answers. The answer—the way—is humility: ontology can continue to strive towards better descriptions (and evaluations) of what there is, but with no claims to saying what cannot be seen, perceived, understood, and said. Its method has to be modest and so will be its results. Its truths must be partial and tentative, and modest answers will perhaps be better than attempts at grandiose visions. Its claims must be relative to smaller portions of reality (or else describe the world in general without much detail), to what can be seen and understood by human eyes, intelligence, and sensitivity, aided with reasoning and logical and scientific instruments.
We now reach a difficulty, perhaps even a dilemma, in our reasoning. Either absolute ontological truths are possible, or they are not. If any absolute ontological truths are possible, then ontology in its traditional form is possible. But can there be any such truths which are not trivial, but substantial and interesting? The question is whether anything true and interesting (substantial) can be said about what there is, in general. The way to answer it is by providing at least one example: if we can give one example of an ontological claim that is both true and interesting (substantial), then ontology in its traditional form is possible. But how can we show that it is certainly true? There seems to be a regress that is difficult to escape: if we cannot show that some (substantial) ontological truth is possible, then we are not yet establishing that progress in ontology is possible. The difficulty is methodological: it seems at least difficult to prove that some (substantial) ontological truth is possible. And this seems to undermine the project of traditional (absolute) ontology. Does it?
In reality, traditional ontology is possible if we allow ourselves to deal with the possibility of error, as in other areas: we may sometimes be mistaken in our conclusions. But the prospects of being right sometimes (even perhaps most of the time, if we observe and think carefully) should count towards optimism, and towards some form of absolute ontology. Of course, we need not be unduly optimistic and embrace grandiose visions just hoping that they will be correct. It is more sensible to proceed modestly and attempt to contemplate first what we can more firmly grasp and proceed from there.
4. What are the implications of ontological facts?
Theoretical progress entails the power to act better. Better knowledge of reality allows us to achieve progress. So ontology allows for the adding of value to reality. Even in areas that are apparently strictly theoretical, greater clarity allows for better vision in general, so progress in ontology brings about progress generally.
Theoretical truth has value—it can do good. Similarly, mistakes in ontology—misapprehensions about what there is—can bring about further mistakes and undue or mistaken action. So it is important that our picture of the world is correct, as mistakes are always bad, and can even be disastrous if spread.
Ontological facts have consequences for the world and for human beings. What there is conditions what we can do with (or against) what there is. Furthermore, what there is may be valuable (requiring protection and promotion) or harmful (requiring some form of prevention). So it is not a matter of indifference what the ontological facts are: they are interesting and substantial, they are possibly necessary, they may influence or even require our decisions. In short, ontological facts matter, so clarity about ontology—about what there is—is important and therefore it is worth considering and investigating seriously and most carefully.
5. Can ontology lead to human progress?
Greater knowledge of the nature of reality is, per se, valuable. And because ontological knowledge enhances our capacity to act positively, its value is also practical. The positive consequences of ontological knowledge may not always be readily evident, but they are a possibility (at least in the sense that knowledge in general is a good).
Because ontological truths can have consequences, knowledge of them can be used to foster human flourishing. A better knowledge of what there is can help promote what is valuable in general, so it can lead to the promotion of human progress.
Of course, ethical considerations should always be in place. Ontological investigations ought to be bound by the needs and priorities of humanity, whilst acknowledging that less urgent investigations can also be ultimately important and even useful, even where they are not urgent and even when they are traditionally (although controversially) seen as ‘idle’—think, for example, of the ontology of art or the ontology of literature, which can have implications, however indirect, for policy regarding the study of these. Pausing to think about ontology may be a privilege in the context of our world, but it can be an opportunity to (directly or indirectly) create value, to make a positive contribution to the world. Its results are not always viewed as successful, or measurable as scientific outputs can be measured. A genuine step forward is this area is hard to achieve and, if substantial and interesting (as any genuine ontological claim will be), it will always be controversial. So the fruitfulness of the endeavour is, in itself, disputable and will be disputed more often than not, as most philosophical enquiries are. But the clarity ontology can provide is certainly a value—a value which may not be obvious to appreciate, which will appear to many of us as controversial and to some of us as useless, but which should not be neglected or dismissed without careful consideration, or we may be throwing away a baby with the bath water.
Ontology remains a worthwhile philosophical discipline: it is a valuable endeavour as it investigates, clarifies, and therefore increases our knowledge of some portion of reality. As a matter of principle, ontological answers should not claim to be always absolute, but the possibility of absolute truths in ontology can be asserted. And because ontological facts have consequences, a sensible ontology can lead to human progress, and should therefore be promoted and pursued.
 This expression is used by Putnam (1990: 117).
 Thanks to the audience at the Joint Session of the Aristotelian Society and the Mind Association (Oxford, July 2018) where this paper was presented.
Putnam, H. (1990) Realism with a Human Face. Cambridge: Harvard University Press.