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Seeing What is in Front of You (Appendix to my 2018 book, Philosophy of Time & Perceptual Experience)

Note: This post is a follow-up to the chapters in my 2018 book about visual experiences of spatially distant things, things that are at some depth in one’s visual experience.  

It is common to talk about the direction of vision, visual direction, or line of sight, and in general where things are located visually. It seems right to say that things seem to be located in a particular visual way to the seeing subject. In addition, there is a particular direction to this appearance, in that some things can be said to be visually off to the side or straight in front of the seeing subject. However, I have problems with deciding what actual or real direction should be used to evaluate this visual appearance. A consequence of these problems is I can only find bad reasons to hold that a visual appearance of direction is inaccurate.

This is a discussion about vision and space, not vision and time. But I think that what I’m going to say here relates to both. The issues for vision and space are very similar to issues for vision and time. The difference is that, for many theorists, time has a direction in a way that space does not.

Accuracy-Conditions of the Visual Appearance of Spatial Direction 

When I stand outside on a clear night with a full moon, the full moon will seem to be a certain distance and in a certain direction from me. This is a particularly visual experience: I (at least seem to) see the moon; I don’t (at least seem to) hear it, smell it, or touch it. One might then ask: is the appearance of the moon’s direction and distance accurate? I don’t like my answer but I don’t know what to do about it. My answer is: except in one possible special way, it is never inaccurate; it is always accurate.

The possible special way is this: if the appearance of the moon’s direction and distance is of it as absolute, then it is not accurate. I assume that apparent direction and distance is highly unlikely to correspond to an actual spatially absolute direction and distance. I do not think that there is absolute direction and distance. Furthermore, if there is an absolute direction and distance, then it would be a matter of chance that appearances correspond to it.

However, I also think that this isn’t clearly how we see the direction and distance of things. If we do, then we can say that this is an erroneous experience of the absoluteness of these spatial properties. For now, whether we have it or not, I’ll put that particular possible experience aside.

This leaves the question I’m interested in: under what conditions is the visual appearance of distance and direction accurate? I am interested in this question because, so far as I can tell, the answer seems to be one of the following:

(a) Visual appearance of direction is inaccurate when it fails to correspond to a relative direction in space.

(b) Visual appearance of direction is neither accurate or inaccurate because there is no fact of the matter about direction. ‘Direction’ is arbitrary.

(c) Visual appearance of (spatial) direction is always accurate because the definition or grounding of direction comes from the appearances, and nowhere else.

For those who want to say that the direction in which something seems is mistaken, (a)  seems best. As there is no absolute direction in space, any attempt to define direction is relative. As with distance or speed, no spatial entity is privileged with respect to spatial direction. It is relative to some points that anything is ‘far away’ or ‘moving fast’. It is also relative to some points that anything is ‘in front of’, ‘behind’, ‘above’, ‘below’, ‘to the left of’, and so on.

So, the appearances can be inaccurate with respect to relative direction. Yet, which relative direction? Determining that is problematic.

In general, appearances can be used to measure something. Appearances can play an epistemological role, where a theory of the world is evaluated by how closely it corresponds to appearances. In that case, appearance is somewhat like a measuring device, such as a metre stick. If we treat appearances that way here, then (c) is to be preferred: one evaluates the direction of something with respect to visual appearances.

However, here, we are asking about the appearances – about the accuracy of the measuring device itself. Ideally, one does not pick the thing being judged to evaluate it. That makes the accuracy trivial, like measuring a metre stick with itself.

So, what do we do? First, maybe we must bite the bullet here and use appearances, i.e., (c). Whether we like it or not, there is no better way of judging actual visual direction. But many may think otherwise: the other options surely can do something here. Either it is (b), there is a relative visual direction independent of appearances or it is (a), there is some absolute visual direction independent of appearances.

Honestly, I think it’s a toss-up between (b) and (c). What weighs the odds in favour of one or the other is whether you want to treat appearances seriously. If you are happy to throw them out (e.g., you hold that appearances never define or ground anything), then go for (b). If you are happy to have them play an epistemological role, go for (c).

However, note that (b) doesn’t provide a direction to evaluate visual appearances against. Instead, it is the position that there is no fact of the matter about a direction. The visual appearance is mistaken insofar as it seems to favour one direction over another. If you say that something seems to be in front of you, or to the side, your mistake is to hold that this could ever be something non-arbitrary – any kind of fact – one way or the other.

So, I think it can be (b) or (c), and I prefer (c) but can say little to dissuade someone convinced by the arbitrariness in (b).

However, I think my suggestion that only (b) or (c) are available should look obviously wrong to at least some readers. One should take (a) — judgement by relative direction — seriously.

For example, surely the very definition of mirages requires accuracy with respect to a relative direction [next section].


Image on by Brahan Milla on Unsplash.

Mirages, as commonly described, are visual experiences where there seems to be something at a particular location in space which is not at that particular location in space. In the most obvious examples, the variation of appearance and reality is typically described as being visually inverted: that what visually seems to be facing one way is actually facing another.

So, in an otherwise empty desert, I see in a small region of the sky, hanging above the horizon in front of me, a street scene — one inverted so that the street occupants’ heads lie below their feet. This is clearly not how they are: they are not walking upside down in the sky. This is an inaccurate visual appearance.

That is a fairly straightforward way of describing the mirage. I imagine it would be risible for many to suggest otherwise. I’m going to suggest otherwise.

The reason I’m going to do that is the account of mirages is more complicated than that it ‘appears upside down and is not upside down’. Once the complications are included, I’m not sure that it’s right to say that things are not how they seem visually. I think that it’s better to say: things are how they visually seem but they do not match expectations of how I might interact with them beyond seeing them. Yet these latter expectations are based on my ignorance of how what I see and what I can touch may interact. This is a multi-sensory error, or an error of multisensory integration, but not of my visual experience itself.

Some examples of mirages:

Visual Illusion/Hallucination

(For more on this section, see my 2018.)

If I believe in elves that can be seen, then I do not hold that the visual appearance of elves is necessarily either an illusion or an hallucination. If I don’t believe in the moon, then I hold that the visual appearance of the moon is necessarily either an illusion (the moon is really something else with wrong apparent properties) or an hallucination (there is nothing there). What you believe is real partly determines your beliefs that how things seem is how things are, i.e., is accurate.

When some experience is an illusion or hallucination, it is in error in some way. As I’ve argued in an earlier post, how it is in error depends (at least in part) on how things appear (a phenomenological condition) and how things are really (a metaphysical condition). What one holds about the latter condition (at least) is theory-dependent. Thus, that there is an error — and what kind — is also theory-dependent.

The error can be different according to different theories even if: (a) everyone agrees as to what is really going on; they need only disagree about what appears to be going on; (b) everyone agrees as to what seems to be going on; they can disagree about what is really going on.

From this, I think that what is erroneous can depend on what one holds to be real about the senses themselves — and the properties we ascribe to them.

Turning this to errors in the direction of gaze (or visual direction), I think that there are three factors to consider:

(a) The definition of the direction of gaze

(b) The possibility of experiential error of direction which it neither illusion nor hallucination (anosognosia).

(c) The possibility of an experiential error of direction at all

Here is my reasoning for taking (c) seriously.

First, as argued elsewhere on the site, I don’t presume the universality of illusory counterparts. Just because something can be apparent doesn’t mean that it can actually be illusory. In the widest set of possible worlds, yes – it’s possible that what’s apparent is merely illusory — but it is an open question with respect to the actual world.

I think that the greater share of claims to error of direction are discrepancies between

(i) The apparent direction of something and

(ii) Its direction relative to a Earth-derived geometric system idealised as a sphere.

However, I also think that there is no particular reason to evaluate the accuracy of (i) by (ii). If one is to evaluate it by anything, it should be

(iii) A direction relative the path along which light travels from the source to the eye.

However, (i) is always accurate when evaluated with respect to (iii) light. That is, if something appears to be straight in front of you in mirages, loomings, or other strange visual phenomena, this is not, strictly speaking, erroneous. By the standard of the path of light itself, it is straight in front of you. This is the case if you choose the path of light from the source to your eye, the very thing that allows you to see the source. If you choose that path, then the source is straight in front of you and even orientated as it appears to be; that apparent direction and orientation is not mistaken.

(You might choose some other path of light to evaluate it, and judge it wrong. Fine — but why? One path of light is as good as another. If you are arbitrarily doing so, then the error here is at best in the absoluteness of apparent direction and orientation (and distance — but I’m ignoring that in this post)).

I think that will sound very wrong to many readers. However, I think, when it comes to considering the alternatives — the body, the world, the head etc. etc. — light is still the better option. All other options lead to cases of error that are intuitively not error. This option leads to cases of veridicality that are intuitively error. Since these cases are also cases of perceptually apparent veridicality (simply by being perceptually apparent) then we have a clash between (a) appearances of veridicality and (b) intuitions of error. In such a clash, where neither side is incoherent, I pick (a) every time.

Let’s look at some alternative ways of picking out the correct direction to judge experienced direction.

They Might be Aliens (Reprinted from Hackcircus magazine #9)

How would we know that we have encountered extraterrestrial intelligence (ETI)? What would distinguish ETI from unintelligent aliens (like the parasite in Alien) and intelligent terrestrials (us)?

It may seem obvious that we can come up with an answer. We know of some intelligent things – ourselves. And we know about extraterrestrial things – planets, stars, interstellar clouds of vinegar.[1] One kind of ETI could be a combination of the two together: things like us, but from space. Consider the tall waving alien at the end of Close Encounters of the Third Kind.

But it is not enough to give an easy example. We cannot assume that the first ETIs we meet will be just like us. And how they might not be like us could make it hard for us to identify them at all.


1 Does It Matter that We Recognise Extraterrestrial Intelligence?

There are a number of reasons to care about whether or not something extraterrestrial we encounter is intelligent or not.

We Ought to Care More About Intelligent Things Than Non-Intelligent Things

Say we encounter something extraterrestrial which has something we want. For example, we come across something on a distant planet with a mineral for fuel. If it is not living, e.g., an asteroid, there seems to be no moral obstacle to simply taking it. Even if it is alive, there is no immediately obvious obstacle. If it is just some kind of extraterrestrial bacteria like the many types of bacteria on earth, there is no ethical question about using it. We take something essential to another living thing every time we eat, no matter how conscientious we find ourselves to be.

However, if ET is in any way intelligent, any way sentient, there are ethical issues. If something has the capacity for self-awareness, it looks safe to assume that it can suffer and there is some moral obligation toward it.

We might not care about that. Even if it suffers or is self-conscious, we may decide to take from it anyhow. We are human after all, and humans have a long history of colonialism and exploitation. If we are ethical, there is a problem with repeating that. But if we don’t care – if we are vicious not virtuous beings, are cruel or numb – then there is no problem.

However, that there is no problem assumes a situation in which we are the ones who are in the position to take from the ETI. We are in the position to conquer, colonise, exploit, or use it. Yet, for ETI, the more likely situation is that the ETI is in the dominant position. It can take something from us. If intelligence only evolved in this Solar System on Earth, it’s more likely that we’ll encounter ETI which is visiting us. If it visits us, it is more adaptable and empowered than we are. It can survive in space, an environment in which we barely exist. If it visits us, it can also enter our atmosphere. It can survive on Earth. Because it can live in space and on Earth, it is more adaptable, more flexible and robust. It is the one that is more capable of taking, of sailing down to us, loading up, and escaping any response from us.

We Can Interact Differently With Intelligent Things Than With Non-Intelligent Things

A second reason to care about recognizing ETI when we meet them is they open up a different set of possible interactions than opened by non-intelligent ETs. You can’t reason with unintelligent things. An asteroid rushing toward the Earth is not slowed down by your sound arguments. Just the same, alien bacteria that chemically synthesizes flesh is unmoved by suffering. However, if you can make yourself understood, an intelligent alien could be stopped doing what it is doing – you could ask it to slow its travel to Earth or to eat something other than your arm.

At least, you can ask it to do that if it recognises you.

2 Recognising Alien Intelligence

One oversight in many (though by no means all) science fiction stories is that intelligent beings that evolve in wildly different environments initially recognise each other as intelligent. Our heroes detect something approaching them and recognise them almost instantly as being sophisticated entities, with consciousness, self-awareness, and even ethical or rational capacities. Yet, when we encounter aliens the first time, there is no guarantee at all that it will look like an intelligent alien. There are several challenges to identifying it as such, including identifying what is not intelligent as intelligent. Furthermore, there is no guarantee that it will recognise us as intelligent beings.

In his short story ‘The Things’, Peter Watts narrates Carpenter’s ‘The Thing’ from the perspective of the alien.[2] It is a compassionate, intelligent being which does not understand humans at all. It is horrified by us. It sees us as empty and blind, lacking sentience, self or feeling.

When we encounter ETIs, it is possible we will not know – and neither will they. When it comes to sharing or taking, whoever has the better position may ignore the other’s cries to stop. This is not because they don’t care about what impact their actions have on other sentient beings; it is because they don’t know there are any such beings there.

So, how could we convince an ETI we are intelligent or sentient? And how could they convince us?


It might be there is one feature that is unique to intelligent beings, even ETIs. Intelligent beings use language. If we encounter an extraterrestrial that uses language, then we know that the extraterrestrial is intelligent.

Here are three ways we might encounter an ETI language:

(a)  There is communication aimed at us by something that understands us.

(b)  There is communication aimed at us by something that does not understand us.

(c) There is communication not aimed at us at all (and which we only coincidentally encounter).


(a) is relatively easy to identify, as easy as a broadcast in a familiar human language. (b) is a common target of SETI and relatively simple as well. Intended for us, it should include patterns strongly indicative of intelligence, patterns which do not naturally occur but which all intelligent beings should know, e.g., sequences of primes. These sequences make sense if ETIs tries to communicate with us.

However, it’s reasonable to think that many – maybe most – ETI signals we pick up, whether we are aware of it or not, are (c). They are messages ETIs are sending amongst themselves. Human-directed broadcasts by humans, such as TV broadcasts or twitter spats, far outweigh ETI-directed ones, such as the Voyager probes. This is something we should also assume is true of ETI. In the first ETI we hear, we are more likely to be overhearing a discussion than have speech directed at us.

Whether or not we recognise it. Given an influential theory of language development, we may not be able to tell eavesdropped ETI conversations from noise.

According to Chomsky’s theory of language acquisition, the linguistic data available to an infant, such as her parents’ speech, is not enough for the infant to learn language. Yet, nearly every infant learns the language which surrounds them. Chomsky posits what Kukla[3] calls the Innateness Hypothesis: An infant is born with something, an innate module, to supplement the environmental data. This module is something that evolved in us; we are born with it, and it is uniquely attuned to the kinds of languages we, as humans, learn. Furthermore, as infants can typically learn any language, this module uses a ‘universal grammar’: typically, all children share a single protean grammar that allows them to learn any language they are exposed to.

Kukla argues that the innateness hypothesis raises a problem with communicating with ETI. Chomsky’s universal grammar applies only to human languages. It is not evidence that any language at all shares the grammar. The grammar may be ‘universal’ for humans. However, whatever structure it has evolves in humans. Any thing lacking the innate module can’t learn it the way one who possesses it can. And if the module is necessary to learn a language its attuned to, then those without it cannot learn that language. If our innate language modules evolved, then we and ETI are unlikely to share the same innate modules. We do not share the same evolutionary history.

One way out of this is convergent evolution. Perhaps the same module and grammar evolves under similar environments. Perhaps those environments exist in other places than Earth. If so, then we may encounter ETI which we can understand and which can understand us. Just as sharks and dolphins resemble each other, or kiwis and rodents, so humans and ETIs resemble each other. However, this is not guaranteed. Where environments are significantly different, creatures don’t so clearly converge in their features. The comparisons are a stretch. (Is the sea cucumber the kiwi of the sea?)

This omits all the other possible environments in which ETI may have evolved. If those other environments are more numerous than the environments like our own, then we are more likely to encounter an ETI from them. We are more likely to pick up their signals. If Chomsky is right, we are unlikely to understand most of the ETIs we encounter.


Perhaps we can avoid using language to detect ETI. If ETI does non-linguistic things that indicate intelligence, then we can still say “that’s intelligent” without it having to speak.

Here is one non-linguistic possibility: ETI exhibits awareness of mathematical, chemical, biological and physical principles. They are more technologically advanced than us. They turn up in gigantic starships hanging effortlessly in the sky. Their hulls are constructed of complex difficult-to-comprehend chemical alloys. When one of them is injured, they heal using advanced medical procedures.

Such traits may convince us that the extraterrestrial before us is intelligent. Advanced technology seems inconceivable without engineering plans, invention, devised and tested theories of physics, chemistry, an understanding of the body.

Yet, only recently did we grasp how bees fly: their flight was once thought impossible.[4]  As the philosopher Dupré notes, not humans but microbes are “the most versatile and effective chemists in the biosphere” (Dupré, p.37[5]). And next time you cut yourself, look at the scar. Your body is repairing itself in a way no current doctor can.

All of these processes occur due to natural evolution — by definition, an unintelligent blind process. They are far more advanced than anything we can do now.

The complex giant ship hanging over your city may be the extraterrestrial equivalent of lichen. Its building of what seem like gigantic ships may be a megascopic lifeform’s growth or reshaping of its immune system.


There is one significant difference between lichen and that ship. Size. Lichen doesn’t grow that big or spread across space. This brings up one of the cheapest moves in most science fiction. We encounter aliens. They are pretty much the same size as us. Untitled3

One of the main reasons Earth life does not grow so huge relative to humans is because of gravity and heat. The different sizes and shapes regulate body temperature, allow movement, and allow creatures to eat. Elephants do not look like mice. Humans have soft tissue on the outside. Without it, when we move we would easily break. Insects, which are smaller, have no need of that tissue. A real Godzilla could not walk or even breath; he couldn’t even cool down.[6]

Yet, ET does not need to be so restricted. It did not evolve here on Earth. If an ET evolved, say, in the depths of an interstellar cloud, it is not clear what size or shape it could be. The morphology and scale of extraterrestrial life, including intelligent life, could vary as widely as extraterrestrial environments allow. (Anyone watching Rick & Morty will find this no surprise.)

The only reason to deny this possibility for intelligent aliens is if intelligence can only survive for any significant time in Earth-like environments. But if intelligence can only survive in Earth-like environments, then no ETI has crossed space to arrive here. Nor can we ourselves ever make it to meet them on their own world, or anywhere in-between.

There is a final way that size and shape might indicate intelligence. If ETI turns out to be the same scale as us, then, given the wide range of options, this would be so much a coincidence that it may be better to think it is intentional. The ET is copying us. It’s difficult to understand how this could be possible through natural selection. They didn’t evolve with us to mimic us. They would have to do it on arrival. The better explanation is they have studied us. These human-sized things may be like costumes worn to raise whooping cranes or fake animals to film animals.[7]

ETI are like us, despite coming from space. This shows they are intelligent. They are able to imitate us, talk like us, convince us they are not anything but another one of us. That would be excellent evidence that these aliens are as smart as we are. Because they are able to be just like we are.

However, if they could do that, then we couldn’t tell them apart from us. Instead of the ‘I’ in ‘ETI’ being difficult to work out, the ‘ET’ becomes difficult to work out. We may finally recognise an ETI as intelligent because it has tried so hard to be like us. But, if it doesn’t recognise us as intelligent, then it is unclear how they would ever take this approach. 

A much earlier and less detailed version of this is published many years ago in Hackcircus #4, 2014.

[1]   http://content.time.com/time/nation/article/0,8599,6778,00.html

[2]   http://clarkesworldmagazine.com/watts_01_10/

[3]   http://www.barnesandnoble.com/w/extraterrestrials-andrz-kukla/1101349873?ean=9780739142448

[4]   http://www.caltech.edu/content/deciphering-mystery-bee-flight

[5]   http://books.google.ie/books/about/The_Constituents_of_Life.html?id=eUqVEiDkzmcC&redir_esc=y

[6]   http://www.cambridge.org/us/academic/subjects/life-sciences/zoology/scaling-why-animal-size-so-important

[7]   https://www.savingcranes.org/raising-cranes.html