What you visually see has no causal efficacy whatsoever

The argument as to why this is so, is very simple and short.

The possibility of visually observing any external object is dependent upon reflected light. And therefore, any object that is visually seen by a given particular observer cannot be the external object which is acted upon or reflected by actual light. For the visible object, a something seen only after the reflection of light, cannot exist prior and external to that state of being something reflected, in order to be a cause of it (or in fact, anything).

 

I mean, I can definitely see how it or you could take the OP to support that conclusion. Yet that wasn't the point of the OP. For it's an argument for what it's said to support; which is, that no visual object has any causal efficacy (either passively or actively) whatsoever.

Although the OP makes no mention of colors, be it blue or red, I wouldn't deny that it calls into question the externality of visual objects all together, namely, causal potency, extensive form, a determinate situation in space, etc.,; rather than only one mere aspect of it (its perceived color).

 

I define those terms as they're commonly understood. The former, (1), as that which can be designated by means of sensible vision. And the latter, (2), as the capability or ability to efficiently effect things external to itself.

How does the reality of the sun challenge the OP? For surely its existence would only, it seems to me, support it. For I don't know how one could argue, let alone prove, that our sight of sun's emission of visible light can antecede the substantial processes granted to be causing it; yet do you ?

 

Wow; talk about someone trying to seem like they know what they're talking about. For example, you ask of me, what "sensible vision" is, I'm presuming with a straight face; and yet go on question my familiarity with the English language ?

Lol, sensible vision is the sentient ability to see (don't go on overthinking this as well). But what does it mean, a novice mind would ask, to "see" (and so on and so on, with such nominal questions, to infinity); without realizing that words by themselves cannot per se express that which they are intended to denote, yet only are capable of referring to them (thus the answer as to what the word "sight" literally means, at some point, becomes axiomatic).

Moreover, you further ask why must an effect be efficient? It doesn't, but what actually effects a change in another thing, as cause to an effect, does. 'Efficient causality' is actually quite a technical term, and not something I just "capriciously" made up in order to sound smart; and usually either the second or third connotation of the term "efficient" on any dictionary website (look for yourself). And so if the OP, and what follows after it, cannot be comprehended by you, this thus is not to be attributed to the supposed obscurity in the diction of the OP, yet rather to your understanding.

Not exactly. An external object must exist prior to any reflection of it; but any object that we visually see is seen only in reflection. Thus, the latter is not the object that's external to the reflected vision of it, which is capable of efficiently effecting or being effected by other substantial things (such as light itself).

 

Yes, sight is a sense, but all sense is not of sight. Thus, the terms "visual sense" and "sensible vision" cannot be redundant words, when considering in contrast to them, the indiscriminate generality of the words "sense" and "sensibility".

You see no semantical difference between the terms causality and efficient causality; well, that's becasue, quite commonly understood, there is none. A cause must be efficient in its effect upon other things; rather than the latter, as you originally mistakenly thought, having to be so.

 

Re-read post #6. My question posed to you there does not use the word "reflect", but "emission"; so indeed, please feel free to try and answer it ?