Being more than one sort of realist
And, quite possibly, being less than all sorts of realist.
We have stirred the pot and faced the difficulties we have with talking about reality. Having used our intuition to guide us in classifying what is real (Re-Assembling Reality #15) we found intuition to be less helpful that we had hoped. We then (in #16) considered other terms like natural (and super-natural), material (and immaterial), and physical (and un-physical). Still, none of these quite scratched the itch. Finally, we picked our way through questions of ontology (#17a), epistemology (#17b), semantics (#17c), symbolism (17d) and experience (#17e).
Faced with such an array of different approaches to realism, which we have so far considered individually, what happens when we put them together?
Summarising the key ideas thus far, the five types of realism we have considered ask five different questions:
Ontological realism: Do things exist outside of my head?
Epistemic realism: Can things be known?
Semantic realism: Can things be described?
Symbolic realism: Can things be symbolised?
Subjective realism: Can things be experienced?
We must stress that these five questions do not do justice to the care, complexity and nuance with which these ideas can be fully formulated. For a start, “thing” is obviously a placeholder for waving vaguely and alluding to “whatever it is we want to talk about.” For a slightly richer treatment, please do follow the links to the other essays and click yourself happy.
In those other essays we generally found that, for any given type of realism, science is realist about somethings and anti-realist about others, and this varies from one branch of science to another and from one scientists to another. We also found that, for any given type of realism, religion is realist about somethings and anti-realist about others, and this varies from one religion to another, and from one religionist to another.
As if that wasn’t complicated enough, we not get to ask questions like, “If a person is ontologically realist about a table, do they also need to be epistemically realist about it?” We will not go through all possible combinations and permutations, but hopefully you will get an idea of how things go.
Why is there not just one type of real?
At the very start of this series (Re-Assembling Reality #5), we considered how wonderfully integrated the Enlightenment view of things was. Any knowledge worthy of the name must be certain knowledge, and must be certainly true. Within such a framework, ontological, semantic and epistemic realism collapse onto one another . Moreover, symbolic and subjective realism become anathema and are dropped from consideration.
In this Essay, we shall consider the bits the enlightenment held onto. In a future Essay we shall pick up the bits the Enlightenment dropped.
Separating ontological and epistemic realism
In a Modernist view, it is hard to separate the knowledge of a thing from the thing itself. Knowledge of a thing is (by definition) true. If it were not true, it would not be knowledge. A person might think that they are Napoleon. They might believe that they are Napoleon. But, if they are not actually Napoleon, they cannot know that they are Napoleon. Things we know are necessary things we know about reality. The external world maps onto the human mind:
“If there is a tree in this field, and if my knowledge is linked to the external world, then I can know there is a tree in this field.”
On this view, ontological realism is inseparable from epistemic realism.
With the rise of postmodernism, the reliability of human knowledge was questioned. Much post-modern philosophy in continental Europe rejected the Modernist idea that our knowledge is reliable, but did not reject the Modernist idea that ontology and epistemology are inextricably linked. The human mind maps onto the external world:
“If I cannot know there is a tree in this field, and if my knowledge is linked to the external world, then there cannot be a tree in this field.”
On this view epistemic anti-realism is inseparable from ontological anti-realism.
The two realisms can be considered independently, provided we reject the Modern idea that there is a perfect mapping between the world and our knowledge of the world. To this end, many favours were done by Alfred Korzybski — an engineer, mathematician, and philosopher — when he made the now famous assertion that,
“The map is not the territory.” 
Our knowledge is not perfect, and the world does not care that our knowledge is not perfect. “Does God exist?” is not the same question as “Do you know that God exists?” Once we insert a wedge between what we know (epistemology) and what the universe is really like (ontology), these two realisms become distinct.
Separating ontological and semantic realism
In a Modernist view, it is hard to separate the description of a thing from the thing itself. If a description of a tree does not map perfectly onto the tree, then it is not a description of the tree; its a description of something else, or a description of nothing. How can we say that a leaf is green if we cannot say it with the words “the leaf is green”? And if the words “the leaf is green” do not mean that the leaf is green, what do they mean? What can they mean?
Around the start of the 20th century, there arose ideas which (using the terminology of this Essay) indicated that one could be ontologically realist about a thing like a leaf, which being ontologically anti-realist about the word “leaf”.
A word is a sign. It consists of a written aspect (the signifier) which can be reproduced on a page, and a conceptual aspect (the signified) which exists in people’s minds. The connection between the signifier and the signified is a socially constructed one: there is noting about the word “leaf” that is particularly leafy, that it should make us think of a leaf .
Language, in some sense, points to things — to leaves and the sensation of seeing green — but it also, and very significantly, it points to other bits of language. A dictionary can define every word in a language without ever once pointing beyond its own covers. The entire discussion of signs is quite independent of the existence of anything mind-independent in the world “out there”.
Alfred Korzybski, immediately after his comments on maps, highlighted this separation of between language and ontology:
“The map is not the territory. The word is not the thing it describes.” 
Part of a map’s usefulness can be found in its similarities with the territory: A line on the map corresponds to a road in the territory. A number on the map corresponds to the elevation above sea level on the territory. But part of the map’s usefulness is found in the differences between it and the territory: One cannot easily view the entire territory at once. One cannot place the territory in a bag and take it home to show a friend where you have been.
Separating epistemic and semantic realism
In prising realisms apart, let us consider how what we know and what we say are not one and the same.
You probably know how to ride a bike. You possibly learned it before you went to school. You know that if you lean on the handle bars in a particular way the bike will steer left. But can you say how to ride a bike?
You cannot. This can be demonstrated by attempting to teach someone to ride a bike by words alone: “Sit on the saddle. Put your hands on the handle bars. Put your right foot on the right pedal. Push it down. Get up off the floor. Sit back on the saddle…” 
Coding a computer to do something used to be the epitome of giving explicit instructions. But it is near-impossible to get a robot to ride a bike. This is why we use machine learning for such tasks. This more or less gives the robot the instruction: “Try stuff. Keep trying different until you stop falling off.”
On the flip side, as well as knowing more than we can say, we say more than we can know.
When Ernst Zermelo and Abraham Fraenkel, set out the axioms of Zermelo–Fraenkel set theory (as discussed in Re-Assembling Reality #17c), what they said could have been written on a postcard. They were unaware of the implications of it, which mathematicians have spent a century working out. They did not know what problems it could be used to solve, what problems could be solved even without it, or what problems it would create. All of these issues were baked in to what Zermelo and Fraenkel said, and yet go very far beyond what they knew.
Combinations and permutations
Now that we have looked at each of these, and seen why they are not all the same, let us consider some examples of how they can arise in combination. I give these as examples of the position that I would take personally. I am not saying these are the right answers, and I am certainly not saying that other people would not strenuously disagree with me. I offer them for what they are worth.
An electron made my detector go ping.
I would be
— Ontologically realist. This is not all in my head. Something is going on in the world “out there”. I may not know what it is, but I am pretty sure that the universe is doing something.
— Epistemically anti-realist. The world is doing something. But science has been wrong about enough things that I would be cautious about nailing my colours to the mast to say I know what it is doing. Certainly not in a strong sense of knowing.
— Semantically realist (sort of). Certainly when I say the detector went ping (or, more likely, click) I really mean exactly that. I also mean that the click was caused by the detector interacting with some particle, which has the properties I associate with electrons. That said, I will admit that my mental image of an electron is almost certainly wrong. I do not know what aspects of it are wrong, or in what ways it is wrong. But it is probably wrong somewhere.
$20 = 2 x $10
I would be
— Ontologically anti-realist. The value of a dollar doesn’t exist outside of human heads. This is all a convention.
— Epistemically realist. Theoretical claims about financial transactions constitute knowledge of the world. Admittedly it is a world that we create in our heads. But I have knowledge of it.
— Semantically realist. When I say that a $20 note has the same monetary value as two $10 notes, that is exactly what I mean.
I am a good person
I would be
— Ontologically realist. Me being a good person (or not being a good person) is not something that society confers on me. Moral goodness exists quite aside from human convention on what is good.
— Epistemically anti-realist. I think I am good. Which is fully consistent with me being good. But it is also fully consistent with me being so proud and corrupted that I am blind to my faults. So which is it? I do not know.
— Semantically realist. When I speak of goodness, I have a particular idea in mind, and I mean pretty much what I say, taken broadly at face value.
I think therefore I am
I would be
— Ontologically realist. I genuinely believe that there exists an “I” which is independent of any human opinion on the matter.
— Epistemically realist. My experience of thinking gives me genuine knowledge of the world. My knowledge of myself is a knowledge which connects with the world.
— Semantically anti-realist. I could tell you what I meant by “I”. But it would be poorly thought through, and I would not suggest that my understanding of “I” got even close to what “I” am (is?) really like.
There is an electron over there
I would be
— Ontologically anti-realist. It is not clear to me that the universe itself knows what it is doing in this situation. If I haven’t measured the electron, the universe may be just as ignorant as I am.
— Epistemically anti-realist. I don’t know what the universe is doing. I can do the calculations regarding when the detector will go ping. But I wouldn’t be sure that any of that maths gives me knowledge of where the electron is before that.
— Semantically anti-realist. What does it mean for an electron to be “over there”? To have a position? I do have a picture in my head. But I would not take that picture at face value.
At the start of this series (Re-Assembling Reality #1) we mentioned that discussions of science and religion often gravitate to questions like “Can you prove that God is real?” If “proof” is something to do with science, and “God” is something to do with religion, then proof of God’s existence would seem to bring science and religion together.
But we should pause for a moment.
Considering the statement “there is an electron over there” I am, anti-realist. Ontologically, epistemically, semantically; whichever way you slice it, I don’t think an electron’s position “exists”.
I have friends who take realist stances towards electrons. Both I and my realist friends have spend many years and many millions of dollars doing experiments with electrons. If we were to hold the terminals of a high-voltage power supply, both of us — realist and anti-realist alike — would be expect to be killed, and most likely we would both be right.
My friend and I can have long discussions (and long disagreements) about realism with respect to electrons. Even while such disputes remain unresolved, we are in perfect agreement when answering the question “Do you want to lick the high-voltage power supply?” As such, there may be more pressing issues than definitively demonstrating that something is (or is not) in various philosophical senses “real”.
At no point in this series will we attempt to prove that God does (or does not) exist. We hope you don’t mind.
This essay and the Re-Assembling Reality Medium series are brought to you by the University of Hong Kong’s Common Core Curriculum Course CCHU9061 Science and Religion: Questioning Truth, Knowledge and Life, with the support of the Faith and Science Collaborative Research Forum and the Asian Religious Connections research cluster of the Hong Kong Institute for the Humanities and Social Sciences.
 Nancey Murphy (1997). “Scientific realism and post-modern philosophy” in Anglo-American Postmodernity: Philosophical Perspectives on Science, Religion, and Ethics. London: Routledge. pp. 39–48. We have drawn heavily on Murphy’s discussion of ontological, epistemic, and semantic realisms, and they manners in which they relate. We find the care with which she teases the three topics apart, and the insight she provides regarding why they are often lumped together, to be wonderfully helpful.
 Alfred Korzybski, (1933). Science and Sanity: An Introduction to Non-Aristotelian Systems and General Semantics. International Non-Aristotelian Library Publishing Company. p. 58
 Ferdinand de Saussure (2013). Course in General Linguistics. Trans. Roy Harris. London: Bloomsbury Academic. Originally published: 1916.
 Alfred Korzybski, (1933). op. cit. p. 58.
 Michael Polanyi (1962). Personal Knowledge: Towards a post-critical philosophy. London: Routledge.