I must say, I am really happy with the way this thread is going. I refrained from presenting the entire thing in one post, because I know that that can be tiresome to read.
One thing that must be kept in mind here is that I am presenting this in piecemeal fashion. The first post dealt with the distinction between deduction and induction. Then, right on cue, Diogenes made the perfect comment to motivate the next part: The distinction between a priori and a posteriori. And now that LG has decided to read what I have written in earnest (thanks for that, by the way), he has spotted the next needful thing: The analytic-synthetic distinction, which I'll get to in the course of responding to LG's post.
We class it as a priori, and I wll explain why shortly.
You're absolutely right, it is different from a posteriori knowledge. The first thing to note is that when I say "a priori" I do not mean "independent of sensory perception". I mean something closer to what the term litearally means: "from first principles". I have no problem accepting "I am thinking" as a first principle.
This gets us to the analytic-synthetic distinction.
Analytic knowledge is that knowledge which a person possesses of propositions solely by virtue of the fact that those propositions are true by definition. "All bachelors are unmarried" is just such an example. Statements expressing items of analytic knowledge have the property that the predicate is already contained in the subject. That is, the predicate adds no new knowledge about the subject, and the statement is seen to be true solely by virtue of the analysis of its terms and logical operators.
Synthetic knowledge, on the other hand, has a very different property. With statements expressing items of synthetic knowledge, the predicate is not contained in the subject, and thus the former does add meaning to the latter. For instance, "George W. Bush is the 43rd President of the United States" is an item of synthetic knowledge. So is, "The Earth is the planet that orbits the Sun with a period of 365.25 days". In both cases, the predicate adds something to the subject. There is nothing about "George W. Bush"-ness that implies "43rd President of the United States" from first principles. Neither is there anything about "Earth"-ness that implies "orbits the Sun with a period of 365.25 days." These statements synthesize two concepts.
Now for the resolution of our conundrum.
With this new understanding, we can classify knowledge in one of three ways:
1. A Posteriori and Synthetic.
2. A Priori and Analytic.
3. A Priori and Synthetic.
The third one is what has been the cause of the most controversy in philosophical circles. I'll go on record as saying that I accept the existence of #3, and I'll further state that I take propositions such as:
I am thinking.
I am perceiving.
I am feeling.
.
.
.
etc.
as examples of #3. As far as I am concerned, the propositions listed above are indubitable first principles, which makes them a priori. It is also the case that each predicate adds meaning to the subject (which is "I"), making them synthetic.
One might ask, "Why is there no a posteriori analytic knowledge?"
To ask the question is to practically answer it: If we do not know something from first principles, then we cannot form immutable definitions about it.
Well, I hadn't really presented "it all" yet, so bear with me.
Of course, you understand that agreement with your ideas is not a priority of mine. If logic dictates that your claims of absolute truth about reality should go, then go they must.
There is evidence for materialism, and it comes from cognitive science. However, that is not the point here. The point is that it makes no sense to ask for a proof that the truth of materialism is certain. In fact, it makes no sense to ask for a proof that the truth of idealism is certain, either. Both metaphysical schools make claims about things that are not known a priori, and no proof can be given as such.
The category error I mentioned has nothing to do with the content of the statements of materialism. I just used that as an example to lure you into this LOL. No, the category error refers to something more abstract and general than that. "Proof" simply doesn't apply to theories that make claims to a posteriori knowledge, because those theories cannot be justified on the basis of conscious awareness and deduction alone.
Asking, "What is the proof of the certainty of materialist claims?" is like asking "How much does blue weigh?" or "What does angry sound like?" or "How far away is happy?"
In other words, it's a category error.
It is readily acknowledged that logic is expandable, and indeed it is being expanded every day by reasearchers in the field. But no amount of challenging or expansion is going to transform invalid reasoning into valid reasoning, and vice versa.
As far as logic being challengable, I have already addressed your comment, and now I will do it again: You are just making a blankent statement of doubt on logic, without explaining why you doubt it. I am not going to entertain the position of the uber-skeptic, who doubts everything including logic. Such argumentation is needlessly contentious just for the sake of being contrary, and it generates all heat and no light. If you have a specific challenge to the rules of deduction, then state it. If not, then let's be done with this part of the discussion.
You are correct inasmuch as a further refinement besides the simple a priori-a posteriori distinction is necessary.
edit: fixed several typos and an underline bracket
One thing that must be kept in mind here is that I am presenting this in piecemeal fashion. The first post dealt with the distinction between deduction and induction. Then, right on cue, Diogenes made the perfect comment to motivate the next part: The distinction between a priori and a posteriori. And now that LG has decided to read what I have written in earnest (thanks for that, by the way), he has spotted the next needful thing: The analytic-synthetic distinction, which I'll get to in the course of responding to LG's post.
lifegazer said:
We class it as a priori, and I wll explain why shortly.
You're absolutely right, it is different from a posteriori knowledge. The first thing to note is that when I say "a priori" I do not mean "independent of sensory perception". I mean something closer to what the term litearally means: "from first principles". I have no problem accepting "I am thinking" as a first principle.
This gets us to the analytic-synthetic distinction.
Analytic knowledge is that knowledge which a person possesses of propositions solely by virtue of the fact that those propositions are true by definition. "All bachelors are unmarried" is just such an example. Statements expressing items of analytic knowledge have the property that the predicate is already contained in the subject. That is, the predicate adds no new knowledge about the subject, and the statement is seen to be true solely by virtue of the analysis of its terms and logical operators.
Synthetic knowledge, on the other hand, has a very different property. With statements expressing items of synthetic knowledge, the predicate is not contained in the subject, and thus the former does add meaning to the latter. For instance, "George W. Bush is the 43rd President of the United States" is an item of synthetic knowledge. So is, "The Earth is the planet that orbits the Sun with a period of 365.25 days". In both cases, the predicate adds something to the subject. There is nothing about "George W. Bush"-ness that implies "43rd President of the United States" from first principles. Neither is there anything about "Earth"-ness that implies "orbits the Sun with a period of 365.25 days." These statements synthesize two concepts.
Now for the resolution of our conundrum.
With this new understanding, we can classify knowledge in one of three ways:
1. A Posteriori and Synthetic.
2. A Priori and Analytic.
3. A Priori and Synthetic.
The third one is what has been the cause of the most controversy in philosophical circles. I'll go on record as saying that I accept the existence of #3, and I'll further state that I take propositions such as:
I am thinking.
I am perceiving.
I am feeling.
.
.
.
etc.
as examples of #3. As far as I am concerned, the propositions listed above are indubitable first principles, which makes them a priori. It is also the case that each predicate adds meaning to the subject (which is "I"), making them synthetic.
One might ask, "Why is there no a posteriori analytic knowledge?"
To ask the question is to practically answer it: If we do not know something from first principles, then we cannot form immutable definitions about it.
Well, I hadn't really presented "it all" yet, so bear with me.
Of course, you understand that agreement with your ideas is not a priority of mine. If logic dictates that your claims of absolute truth about reality should go, then go they must.
There is evidence for materialism, and it comes from cognitive science. However, that is not the point here. The point is that it makes no sense to ask for a proof that the truth of materialism is certain. In fact, it makes no sense to ask for a proof that the truth of idealism is certain, either. Both metaphysical schools make claims about things that are not known a priori, and no proof can be given as such.
The category error I mentioned has nothing to do with the content of the statements of materialism. I just used that as an example to lure you into this LOL. No, the category error refers to something more abstract and general than that. "Proof" simply doesn't apply to theories that make claims to a posteriori knowledge, because those theories cannot be justified on the basis of conscious awareness and deduction alone.
Asking, "What is the proof of the certainty of materialist claims?" is like asking "How much does blue weigh?" or "What does angry sound like?" or "How far away is happy?"
In other words, it's a category error.
It is readily acknowledged that logic is expandable, and indeed it is being expanded every day by reasearchers in the field. But no amount of challenging or expansion is going to transform invalid reasoning into valid reasoning, and vice versa.
As far as logic being challengable, I have already addressed your comment, and now I will do it again: You are just making a blankent statement of doubt on logic, without explaining why you doubt it. I am not going to entertain the position of the uber-skeptic, who doubts everything including logic. Such argumentation is needlessly contentious just for the sake of being contrary, and it generates all heat and no light. If you have a specific challenge to the rules of deduction, then state it. If not, then let's be done with this part of the discussion.
You are correct inasmuch as a further refinement besides the simple a priori-a posteriori distinction is necessary.
edit: fixed several typos and an underline bracket
