Here are some posts I wrote today trying to explain what he was saying. I still have not figured it out, but maybe you or someone else can see where I keep messing up.[/color]
I started to answer yesterday, [but I ran into problems and gave up][/color] but it's difficult to tell what he's saying as he seems to use terms inconsistently. Of course, that may just be because I haven't read everything up to that point. I can tell you what I think he's trying to say, but I can't guarantee it will be accurate.
Think of the situation in terms of (X) inputs, (Y) mechanisms, and (Z) outputs. As the first example (1), consider seeing an apple. The input is the apple, the mechanism is your visual system, and the output is your visual image of the apple.
As the second example (2), consider remembering your visual image of the apple. The input is your visual image of the apple, the mechanism is your memory system, and the output is your memory of your visual image of the apple.
So 1X would be "the apple", 2Y would be "your memory system", and so on.
Now, 1Z and 2X are the same thing- your visual image of the apple- but they are in different examples. Try to put them in the same example, (3), as both the input and output: 3X is your visual image of the apple, 3Z is your visual image of the apple, but what is 3Y? He is saying that no 3Y will work in that example- the example is impossible. He is led to that conclusion because he assumes that every one of your experiences is the output of some mechanism that was given some input; It always works the same way: input -> mechanism -> output, X -> Y -> Z. He also assumes that the input and output are never equal in the same example (E); EX never equals EZ. Imagine that EX and EZ are as similar as possible. EZ is EX
after EX has passed through EY. So, with another assumption (that passing through the mechanism takes time), EX and EZ are at least separated by time. I don't know how he justifies these assumptions though.
Anyway, it is rather easy to see in situations like the first example, where we are perceiving something "outside" of our brain, that there is some intervening mechanism between the (external) input and the (internal) output. It is rather easy to see that 1X and 1Z cannot be the same thing- there is some intervening mechanism, 1Y. It is this intervening mechanism that makes all ideas subjective.
It may not be so easy to see that the same is true- that there is some intervening mechanism- when both the input and output are internal. But he is saying that such is the case. See the paragraph on the next page that starts, "The answer to that question..."
A cognitive idea (including here percepts, memories, images, and concepts) cannot, at one and the same time, be both that which we directly apprehend and that by which we apprehend something else- some object that is not an idea in our own minds, but unlike our subjective ideas is rather something that can be an object of consideration or conversation for two or more individuals.
Now, "something else- some object..." is EX. "that which we directly apprehend" is EZ, "that by which we apprehend something else" is EZ, and [I ran into problems and started over][/color]
Think of the situation in terms of (X) inputs, (Y) mechanisms, and (Z) outputs. The outputs are what he calls "ideas". He is saying there need to be two levels of ideas- level 1 and 2.
As an example of a level 1 idea, consider seeing an apple. The input is the apple, the mechanism is your visual system, and the output is your visual image of the apple.
As an example of level 2, consider remembering your visual image of the apple. The input is your visual image of the apple, the mechanism is your memory system, and the output is your memory of your visual image of the apple.
So 1X would be "the apple", 2Y would be "your memory system", and so on. Again, 1Zs and 2Zs are both what he calls "ideas". 1Zs are what he calls "objects of apprehension", 2Zs are what he calls "cognitive ideas". The distinction is made by looking at 1Xs and 2Xs. 1Xs are not ideas. 2Xs are ideas.
(I'll use page numbers of the edition on Amazon.) The paragraph on page that starts, "The answer to that question...":
A cognitive idea (including here percepts, memories, images, and concepts) cannot, at one and the same time, be both that which we directly apprehend and that by which we apprehend something else- some object that is not an idea in our own minds, but unlike our subjective ideas is rather something that can be an object of consideration or conversation for two or more individuals.
What we already know, translated:
"A cognitive idea"= a 2Z.
"something else"= a 1X.
"that by which we apprehend something else"= ?
"that which we directly apprehend"= ?
From pages 13-14:
All these [1Zs] are objects of immediate experience. They do not serve as means for apprehending anything else. They themselves are the objects of our apprehension.
With these exceptions noted, all our other ideas can be characterized as cognitive [2Zs]- as instruments of cognition. Instead of being themselves objects of apprehension, they are the means by which we apprehend objects that are not ideas.
So it seems "that by which we apprehend something else"= a 2Z.
"that which we directly apprehend"= a 1Z.
To check this [ran into problems and started over, ran into problems with that one and started over][/color]
Think of the situation in terms of strings of inputs (X), mechanisms (Y), and outputs (Z). Call "X -> Y -> Z" a string. The Zs are what he calls "ideas". He is saying there need to be two levels of ideas: levels 1Z and 2Z. We can accomplish this by defining two levels of strings: "1X -> 1Y -> 1Z" and "2X -> 2Y -> 2Z".
As an example of a level 1 string, consider seeing an apple. The input is the apple, the mechanism is your visual system, and the output is your visual image of the apple.
As an example of a level 2 string, consider remembering your visual image of the apple. The input is your visual image of the apple, the mechanism is your memory system, and the output is your memory of your visual image of the apple.
So 1X would be "the apple", 2Y would be "your memory system", and so on.
Again, 1Zs and 2Zs are both what he calls "ideas", but he makes a distinction between them. 1Zs are what he calls "objects of apprehension". 2Zs are what he calls "cognitive ideas". The distinction is made by looking at 1Xs and 2Xs. 1Xs are not ideas. 2Xs are ideas. (You can also consider the Ys, but I won't go into it here.)
Using the page numbers of the edition on Amazon, from the paragraph on page 15 which starts, "The answer to that question...":
A cognitive idea (including here percepts, memories, images, and concepts) cannot, at one and the same time, be both that which we directly apprehend and that by which we apprehend something else- some object that is not an idea in our own minds, but unlike our subjective ideas is rather something that can be an object of consideration or conversation for two or more individuals.
So what we already know, translated:
"A cognitive idea"= a 2Z.
"something else"= a 1X.[/color]
From pages 13-14:
All these [1Zs] are objects of immediate experience. They do not serve as means for apprehending anything else. They themselves are the objects of our apprehension.
With these exceptions noted, all our other ideas can be characterized as cognitive [2Zs]- as instruments of cognition. Instead of being themselves objects of apprehension, they are the means by which we apprehend objects that are not ideas.
and on page
So it seems "that by which we apprehend something else"= a 2Z.
"that which we directly apprehend"= a 1Z.[/color]
Giving us so far:
A 2Z cannot, at one and the same time, be both (a 1Z) and (a 2Z with a 1X as input)
Now it seems "at one and the same time"= in the same "X -> Y -> Z" string.[/color] In other words, there have to be two levels of strings: 1X -> 1Y -> 1Z and 2X -> 2Y -> 2Z, giving us the two levels of ideas.
[ran into problems and started over- with a different approach][/color]
Using the page numbers of the edition on Amazon, from pages 13-14:"It is necessary to remember that the opposing view does not apply to all ideas, but only to some. Excluded are bodily sensations, feelings, emotions, and, in rare instances, sensations generates by stimulation of our external sense-organs. All these are conceded to be private experiences, in which we are directly conscious of the pain we feel, ... All these are objects of immediate experience. They do not serve as means for apprehending anything else. They themselves are the objects of our apprehension.
With these exceptions noted, all our other ideas can be characterized as cognitive- as instruments of cognition. Instead of being themselves objects of apprehension, they are the means by which we apprehend objects that are not ideas."[/color]
From the paragraph on page 15 which starts, "The answer to that question...":
A cognitive idea (including here percepts, memories, images, and concepts) cannot, at one and the same time, be both
that which we directly apprehend and
that by which we apprehend something else- some object that is not an idea in our own minds, but unlike our subjective ideas is rather something that can be an object of consideration or conversation for two or more individuals.[/color]
So we have cognitive ideas (CI) and noncognitive ideas (NI). NI "do not serve as a means of apprehending anything else."[/color]and "are the objects of our apprehension"[/color] CI "are the means by which we apprehend objects that are not ideas."[/color]
[This is where I am now, but I'm stopping for a while- it is driving me mad.][/color]