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A priori and empirical knowledge

Empiricism is the thesis that all of knowledge is based upon and/or justified by sensory experience. When you really consider it, you will likely be aware that from step 1, this thesis cannot get off of the ground. In the first place, we have the a priori basis of mathematical knowledge, which entirely conflicts with this thesis. In the second place, we have the method of necessarily truth-preserving deductive proof and logical demonstration, which once again conflicts with the inductive nature of empirical inferences and conclusions. The reason I bring this up is that it is often parroted that knowledge must be based upon empirical observation or "the empirical evidence". However, it remains open to question to what extent such dogmatic assertions are really true. You can prove the irrationality of the square root of 2 without ever leaving your arm chair, and no one would assert that this proof doesn't constitute a valid piece of knowledge. People are more inclined to say that we couldn't arrive at valid conclusions about the world without the justification of experience. Really? Nothing is simultaneously red all over and green all over. There; I came to a valid conclusion about the world without ever leaving my arm chair. Someone may object "..but you needed to observe some particular object to come to this conclusion". Perhaps, but simply because I have to acquire some knowledge on the basis of sensory experience, doesn't mean I have to justify it on the basis of sensory experience. You do not need to justify the proposition empirically to see that it is true. All you have to do is resort to the logical reasoning that nothing is simultaneously X and (not)X (i.e. the law of non-contradiction). Make no mistake; I have no doubt that one must indeed test certain tentative hypotheses against empirical observation to determine their correctness. Nonetheless there seems to be a kind of myth that all valid knowledge must be based on experience, and yet this argument simply can't get off the ground.

Re: A priori and empirical knowledge

Hi xyz. Your challenge to empiricism is glib, but sophistical. Logic and mathematics are based on rational insight, which is a kind of "experience" in the larger sense, a non-phenomenal sort of experience. Reason was for this reason called by the ancients, in both West and East, the sixth or common sense, i.e. the sense-organ that ties together the other five senses, those that bring us in empirical contact with phenomenal experience: colors, shapes, sounds, smells, tastes, touch-sensations, etc. The five senses without the sixth yield chaotic nonsense (they are non-sense, one cannot make sense of them); and conversely, the sixth sense is useless without the other five, because it has nothing about which to have rational insights. As with all irrational skeptics, your discourse looks superficially coherent, but what it lacks is the reflexive act of "turning it on itself." When in logic or mathematics we speak in formal terms, using symbols like X or Y, or in material terms (e.g. with specific numbers), we even then rely on experience - for a start the material experience of one's physical or mental symbols (which are all phenomenal), and also the more subtle experience of one's rational insights (which are non-phenomenal). You cannot just ignore the experience of your symbols or words that you rely on, let alone all the experiences which make your discourse at all possible. Look at all the words and sentences you have written in your post, and ask yourself which one of them is at all thinkable or speakable or writable or understandable without resorting to experience. Not a one! Empiricism is no myth or dogma, as you try to claim, but a mere recognition of the fact that knowledge without "external" (be it physical, mental or intuitive) data is simply impossible. Anyone who honestly looks at the facts of the case, without leaving out relevant information and assumptions, cannot but admit this. Ask yourself too why it is you so dearly want to deny empiricism, and what alternative theory of knowledge you have to offer. A bit of introspection would do you good. But most of all keep in mind what I said above, that you cannot talk or Xs and Ys, or of 1-2-3, without relying on experience, both of the phenomenal and the non-phenomenal kinds. Logicians and mathematicians who think their discourse is 100% a priori are idiots. There is no such thing as purely analytical truth. Read some of my essays on these subjects, e.g. in my book Phenomenology or in my book Logical and Spiritual Reflections (at www.thelogician.net) - with an open, truth-seeking mind.

Something about you (optional) logician-philosopher

Re: A priori and empirical knowledge

In all fairness, you may have missed the point of my post. I am not stating that empiricism is false, so much as I am stating what might be called "naive empiricism" is false (e.g. the claim that knowledge is 100 percent based upon sensory experience). As you yourself have noted, rational intuition can certainly be described as experiential, but in a non-sensory or non-phenomenal form. My point of course, was not that all of mathematics was entirely composed of a priori analytic truths, but merely that one need nowhere rely on any form of sensory experience to justify any mathematical proof; you can of course make exceptions for rational insight as a form of "experience" if you so wish. I have often heard one state that "any scientific knowledge must be based upon the empirical evidence" or that "one cannot come to any valid conclusions about the world based on pure reason alone". These claims are contentious, as they are not so much arguments as they are assumptions. So you see, my post is not a condemnation of empiricism, so much as it is a condemnation of the more naive forms of empiricism that certain people seem rather keen on espousing these days. Of course, without experience, knowledge would be utterly impossible. I'm somewhat surprised that you took my post to be a full-blown condemnation of empiricism, when my first post actually stated: "I have no doubt that one must indeed test certain tentative hypotheses against empirical observation to determine their correctness..."

Re: A priori and empirical knowledge

Hi again. I am glad we agree. Actually, I did notice your statement "one must indeed test certain tentative hypotheses against empirical observation to determine their correctness" but I read you as intending to apply this principle of induction in some but not all cases - whereas I would regard this as a general principle, which may be used (if only heuristically) for quality control of all knowledge. That is how I interpreted your whole intervention - as an attempt to put in partial doubt, rather than sweepingly deny, empiricism. I did not realize you were intending to attack pure empiricism (which is what "logical empiricism" advocates) - i.e. empiricism without resort to rational insight. If this is your intention, why then say the following? "I have often heard one state that "any scientific knowledge must be based upon the empirical evidence" or that "one cannot come to any valid conclusions about the world based on pure reason alone". These claims are contentious, as they are not so much arguments as they are assumptions." There is nothing contentious about these two statements you quote. They are not intended as arguments or assumptions - they are logically obvious as I have already stated. There is no such thing, to repeat, as purely analytical truth (which concept is also advocated by "logical empiricists," based on Kant's dichotomies). The answer to the problem here dealt with is to approach the issue of knowledge "phenomenologically" - i.e. by starting from "appearances" rather than characterizing appearances as "sense-data" from the outset, or even trusting all rational insights without possibility of verification. If all knowledge is based on appearances, then the ordering of knowledge is also based on appearances, and the most consistent theory of knowledge can be relied with confidence.

Something about you (optional) logician-philosopher

Re: A priori and empirical knowledge

I think much confusion arose from a difference in terminology. My usage of the word empiricism corresponded to: (1) Empiricism - the view that knowledge is entirely based upon sensory experience, independent of rational intuition or a priori knowledge. However, you seemed to be using empiricism more in line with the following definition: (2) Empiricism - the basing of principles of knowledge upon the existence of experience, including both rational and sensory experience. Likewise, I believe the usage of the word "evidence" was being used in two different senses. I was using the word evidence in line with definition (1) (i.e. the evidence of "raw sense-data", independent of rational reasoning). All I am doing is objecting to the position known as "empiricism", according to definition 1. That is, those would deny that rational or a priori reasoning has any epistemic force (i.e. has any basis with respect to knowledge claims). That is all my point ever was: that both a posteriori and a priori reasoning are important when it comes epistemology. Hopefully this clarifies matters.

Re: A priori and empirical knowledge

Hi xyz. Thank you for your clarification. The way you put it here, in your latest post, viz. "All I am doing is objecting to the position known as "empiricism", according to definition 1. That is, those would deny that rational or a priori reasoning has any epistemic force (i.e. has any basis with respect to knowledge claims)." This I would agree with. My position is that extreme empiricism (like E. Mach's), which denies the efficacy of rational discourse, is untenable, since it itself involves rational discourse in justification, i.e. it is self-contradictory. Also, the opposite extreme, the position that it is possible to produce knowledge (logical or mathematical) by purely analytic / a priori means is also an absurdity, since it resorts to perceptions of symbols and words, which are themselves empirical objects, and because all words and symbols ultimately depend on perception for their meaning anyway. I should add that when we speak of sense-data, we should think of both the primary data perceived through the senses at the time of actual physical perception, and secondly of the memories and thence imaginations derived from the preceding. These mental objects, which are phenomenal, are also strictly-speaking sense-data, since they cannot be produced without having some physical experience first. The preceding are "phenomenal" data. The data of rational insight can be said to be a third type of empirical data, distinctively non-phenomenal, through which we think logically and build concepts and propositions. However, it is important not to reify this "data" - we must keep in mind that it is intentional, it is process.

Something about you (optional) logician-philosopher

Re: A priori and empirical knowledge

Continuation: Nevertheless, xyz, I want to return to your earlier statements. You said: "In the first place, we have the a priori basis of mathematical knowledge, which entirely conflicts with this thesis [Empiricism]. In the second place, we have the method of necessarily truth-preserving deductive proof and logical demonstration, which once again conflicts with the inductive nature of empirical inferences and conclusions." What I object to here is your belief that purely analytic / apriori knowledge is possible. This is a commonly held view nowadays, since Kant, but it is false, untenable. You say: "The reason I bring this up is that it is often parroted that knowledge must be based upon empirical observation or "the empirical evidence". However, it remains open to question to what extent such dogmatic assertions are really true. You can prove the irrationality of the square root of 2 without ever leaving your arm chair, and no one would assert that this proof doesn't constitute a valid piece of knowledge." Here again, you are affirming the possibility of purely apriori mathematical knowledge, forgetting that the concepts involved in this proof are all ultimately based on experience. The rational insights that produce the proof are only the last links in a long chain. Again: "People are more inclined to say that we couldn't arrive at valid conclusions about the world without the justification of experience. Really? Nothing is simultaneously red all over and green all over. There; I came to a valid conclusion about the world without ever leaving my arm chair." Here, you think the law of non-contradiction can by itself produce knowledge. You forget that your statement would be incomprehensible to you or anyone who had not first empirically come to the concepts of "red, green, all over, is, nothing, and", not to mention "world, arm-chair, etc." You can't just ignore these antecedents in your thinking. So, whereas you do not take the extreme empiricism position that knowledge can come from empirical physical data alone, you do take the opposite extreme and think that knowledge can come from rational insight alone. This is the point of contention between us.

Something about you (optional) logician-philosopher

Re: A priori and empirical knowledge

I was somewhat hesitant to continue the discussion. I mean no offense, but I feel like the discussion turned out being rather protracted and confusing. I somewhat regret starting it, due to the confusion it ended up leading to. You are correct in that I do accept (a priori) analytic knowledge. For example, I do accept the sentence (e.g. "All bachelors are unmarried") as an analytic truth; I do accept that you can understand this proposition strictly by virtue of the meaning of the terms involved. In other words, I do accept that there are certain truths of reason that are self-evident, and intuitively graspable. I do not deny, of course, that in order to grasp certain truths of reason, one must look at dots of ink on a piece of paper, for instance. In order to understand the proposition "all bachelors are unmarried", one must of course be able to read the words on the page; but I do not believe that this has any bearing on the justification of the proposition as a priori knowledge. You are correct that this is the essential point where we disagree. Whether this means that I am going to the "opposite extreme", I am not so sure. In any case, I enjoyed the discussion even if it did lead to a rather significant amount of confusion.

Re: A priori and empirical knowledge

Permit me to reply to your two last points. Concerning "bachelors are unmarried men", please look here: http://www.thelogician.net/6_reflect/6_Book_2/6b_chapter_02.htm The proposition "bachelors are unmarried men" may appear in people's minds in one of two ways. Either (1) we arrived empirically at the idea that "there are unmarried men" and then decided to attach a name to this phenomenon, viz. "bachelor"; or (2) we found texts about "unmarried men", and other texts about "bachelors" and eventually realized from context that the two terms are equivalent. In case (1) although the new name being attached is a conventional act, there is no added knowledge, and it is ridiculous to speak of "analysis", not to mention that "unmarried men" is a concept based on experience (of men, of the social institution of marriage). In case (2) the tying together of two separate threads is not an "analytic" equation but an inductive act based on observation of contexts of use, and understanding of these contexts depends on experience of course. Try doing all that with the content-less "C are BA" - is even this analytic truth? As regards, taking into consideration the perception of "words on the page" as you put it - this relates to mathematical proofs. Many mathematical proofs are based on the manipulation of symbolic objects (whether as ink on paper or dots on a computer screen or in mental imagination). The behavior of these symbolic objects are effectively the empirical basis of the mathematical principles. The fact that physical objects like apples or mental objects like imagined apples are not used, but symbols like a, b, c changes nothing to the empiricism involved. Without the visualization of something there is no mathematical proof. So it cannot be said to be purely analytical, i.e. purely based on rational insight, without any content whatsoever. Similarly in logic - the laws of thought have no meaning if not "applied" to something more concrete. Even spoken in terms of symbols (as in "A is A") their meaning proceeds form the concrete percepts involved (A, is). As I said before, to ignore some elements of one's own discourse, and try to formulate philosophical, logical or mathematical ideas without taking into account ALL its constituents, is idiocy.

Something about you (optional) logician-philosopher

Re: A priori and empirical knowledge

Interesting discussion! So is there any merit in the "Analytic-synthetic" distinction?

https://en.wikipedia.org/wiki/Analytic–synthetic_distinction

According to Kant,a proposition whose predicate concept is contained in its subject concept is analytic, and a proposition whose predicate concept is not contained in its subject concept but related, is synthetic. The term "related" seems a bit vague here - related in what way?

an example of an analytic proposition is: All bachelors are unmarried
an example of a synthetic proposition is: All bachelors are alone

But both subjects here refer to the meaning of "bachelor", and the so-called synthetic proposition can be deduced from the analytic one.

To me it all seems like much ado about nothing.

Re: A priori and empirical knowledge

Hi McCoy - there's no such thing as purely analytic propositions (i.e. not based on experience) - all are synthetic to some extent (i.e. based on experience). Kant was a brainy guy, but in many ways also confused. If you have not read my little book "A short critique of Kant's unreason," I recommend it.
My main website is having tech problems right now, but you can read it here: http://tl-archive.net/6_reflect/6_Book_2/6_book_2.htm