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 either,
(a) Visual appearance of direction is inaccurate when it fails to correspond to an 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, speed, etc., 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. Ideally, one should not pick the thing being judged, i.e., visual appearance. Yet, picking anything else is equally problematic. I’ll show this by discussing a plausible candidate: the eye.
Given the epistemological role of appearances, I think (c) is to be preferred: one evaluates the direction of something with respect to visual appearances. However, 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).
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, take mirages [next section].