William O

I want to underline this point a bit because until just now I was under the impression that marijuana is not addictive, but I did some Googling when I read your post, and several seemingly reputable sources report that it is potentially addictive. This article compares it to alcohol in the sense that most people use it without becoming addicted, as a way to relax from time to time, but some people become addicted and start using it so compulsively that it interferes with living a full life. https://www.psychologytoday.com/blog/almost-addicted/201311/is-marijuana-addictive

I will participate, and I have ordered the book. I am a college student near the end of a BA in philosophy, which I will have after I write my senior thesis next semester. I am also working on a degree in computer science.

Thanks for mentioning this. The review is available online, but apparently it requires a subscription to read the whole thing. http://www.nybooks.com/articles/archives/2009/sep/24/why-should-you-believe-it/ Here are a couple of responses to Searle's review, along with his responses in turn. http://www.nybooks.com/articles/archives/2009/dec/17/fear-of-knowledge-an-exchange/

I have recently finished reading Fear of Knowledge by Paul Boghossian, and I highly recommend it. It is a short book defending the claim that there is an objective reality independent of anyone's beliefs about it against relativism, primarily against the relativism of Richard Rorty. The book has three main sections. In the first section, Boghossian addresses the claim that reality is socially constructed. In the second section, he addresses the claim that epistemic norms are mere constructs - that is, for example, there is no way to demonstrate the inferiority of an epistemology that is based on the infallibility of the Bible. The third section addresses the claim that all of our beliefs have non-rational psychological explanations in terms of our desires and interests apart from the evidence, which is a claim that is popular in the field of sociology of knowledge. Boghossian's approach to these positions is usually to argue that they are self referentially inconsistent. He goes into some detail about how the charge of self referential inconsistency applies specifically to each form of relativism. In particular, he is careful to show that Rorty's sophisticated version of relativism is not immune to the criticisms that refute more naive versions. I think Objectivists will like this book, since it is a defense of the fundamental axiom of Objectivism and it doesn't use any arguments that an Objectivist could not safely endorse.

One possibility is simply overthinking the issue. One time I was interested in the relationship between a certain pair of concepts, so I wrote out my thoughts at length, using a number of carefully chosen examples and distinctions. The next day I looked at what I had written and I realized that the two concepts were just synonyms. It's a seductive error to make because you start developing distinct accounts for both concepts and it feels like you're making progress when actually you're just playing with words.

Mathematics is About the World by Robert Knapp is a book that discusses this sort of issue at length, written by an Objectivist mathematician.

I love this point.

I just thought of something that I'd like to add to the discussion here. Modern logic has a rule called disjunction introduction that allows you to add any disjunct to a premise. For example, if I affirm "the grass in my yard needs mowing," then this rule allows me to directly infer "either the grass in my yard needs mowing or Martians are invading the earth." In most contexts, this sort of inference is a violation of Rand's rule that arbitrary statements should be rejected without consideration. As a result, the widespread acceptance of modern logic in academic philosophy has led philosophers to think that the Gettier problem is a serious concern. One version of the Gettier problem occurs when I start with a justified belief I hold that I don't know is false, then arbitrarily introduce a disjunct that I think is false but which is actually true. The result is a true, justified belief which is nevertheless not knowledge. Academic philosophers have spent an enormous amount of effort over the last several decades trying to figure out how this can be possible. So, modern logic isn't just useless to philosophy, it's actively harmful. It's just a set of rules we built computers to obey that produce confusion when they are used as a guide for how to think.

I agree that Hume's epistemology is pretty similar to how an animal's mind functions, so that would be a good point.

I disagree with your claim that someone can't be 100% empiricist, because empiricism is a specific psychological trait of which there are clear examples. An empiricist uses abstractions just like everyone else - a person without abstractions isn't an empiricist, they are some sort of invalid. The difference is that the empiricist is much more reluctant than is objectively necessary to draw an abstraction.

So you think it's basically a stolen concept fallacy?

I wouldn't say Kant got anything right, so in that sense he didn't contribute anything of value. However, Kant's work has had a profound influence on every area of philosophy for centuries, so it is harder to understand the history of philosophy if you haven't studied Kant. For example, Marx was heavily influenced by Hegel, who took the inspiration for a lot of his philosophy from Kant. None of these are good guys, to be sure, but they are part of the history of philosophy, and their ideas continue to influence our culture.

Most Objectivists would probably assume that empiricism is inconsistent with forming broad abstractions. ("Empiricism" here is used in the sense of the psychological tendency defined by Rand which focuses too heavily on concretes.) I think that this assumption about empiricism is false, because empiricists have historically appealed to broad abstractions as a foundation for their empiricism. To illustrate, here is an example from Hume: Hume is here drawing a fairly broad abstraction known as "Hume's fork," but his overall argument is clearly empiricist. What makes his argument empiricist rather than rationalist in spite of the fact that it is based on a broad generalization is that the broad generalization tends to disintegrate rather than integrate what we know. Empiricism does not necessarily differ from rationalism in that it contains principles, but in that any principles it does adopt tend to force us to rely more on concretes, e.g., the reduction of the entities we observe to sensory impressions.

I took the conclusion that it was arbitrary from the fact that Carnap uses the word "stipulation" and my background knowledge about logical positivism. Thanks. I haven't brought up logical positivism's view of theoretical entities yet, although that's worth discussing. I have been reading an essay by Moritz Schlick that affirms the existence of atoms, which I was under the impression most logical positivists regarded as meaningless. Maybe the issue had been resolved by 1932, when the essay was written.

Carnap explains his view about the relationship between language and observation statements very clearly in this paragraph. He explicitly says that the deductive relationships are arbitrary. This is from Carnap's essay "The Elimination of Metaphysics Through Logical Analysis of Language," from A. J. Ayer's anthology Logical Positivism, on page 63.

I like the idea that logical positivists insert language between perception and concept formation, Eiuol. Several of the logical positivists in this anthology have made a point of saying that there is no way to affirm the existence of an entity in modern symbolic logic. You can affirm the existence of an entity with a certain property in modern symbolic logic: (∃x)Fx affirms the existence of at least one x with the property F. But you can't affirm the existence of x by itself, because modern symbolic logic can't handle proper names. The logical positivists take this to be a reason to reject claims like "the external world exists" and "I think, therefore I am." Both of these affirm the existence of a proper name, i.e., the external world or you. Affirmations of the existence of entities should allegedly be rejected in favor of descriptions of regularities in one's sensory data, because those regularities can be described qualitatively and translated into modern symbolic logic. So, first comes the perception of the entity, then symbolic logic steps in and requires you to deny the entity in favor of a regularity in your sensory data, and finally you form the concept or draw whatever conclusions you were going to draw from the perception.

This isn't quite what you're asking for, but there are statistical techniques you could use to approximate the overall composition of the bag of marbles if you took several samples from the bag consisting of, say, ten marbles each. That would be sort of like calculating the metaphysical probability from the epistemological probability. We do these sorts of statistical calculations to evaluate experiments about, e.g., the metaphysical probability that a medicine will cure someone, so it's certainly an important issue.

What I was suggesting with the claim that they take theoretical physics as a revelation from God was that they take advanced claims in physics out of context and then demand that obvious everyday facts be derived from them in order to be legitimate. I wasn't referring to logic, although that would also be a fair comparison to make. I haven't read anything by Carnap apart from the essay I mentioned in the OP, but the impression I got was that he has a different take on reducing things to observation than Objectivists do. It seems like he thinks that the meaning of a word is identical to the sentences it is deducible from and the sentences that are deducible from it, and these deductive relationships can be stipulated however we want depending on what is convenient. Carnap's position is similar to Rand's insofar as they agree that a term that can't be reduced to observation is meaningless, but for Carnap reduction seems to be less a matter of relating a concept to empirical evidence and more a matter of language. For example, if you asked Rand and Carnap whether it is meaningful to say that gravity exists, Rand would go about the matter by asking for the experiments that support the existence of gravity and prove that it is a valid concept, whereas Carnap would just ask whether you have stipulated a set of observation statements that can be deduced from the claim that gravity exists. The two positions represent a pretty big difference in attitude even if they have some of the same consequences.

Yes, I also think that there is a similarity there. I think logical positivists have a different concept of observation than Objectivists do, though. It seems like they don't distinguish between claims that are supported by so many observations that there is no way to argue for them, like the axioms of metaphysics, and arbitrary assertions based on emotion. I read that logical positivists didn't even accept the objectivity of sensory perception, in a sense - they regarded the structure of a perception as objective, but not the conscious content. So for example, if I see a chair, the fact that I am seeing a chair is objective, because a chair is a structure that can be conveyed to other people explicitly, but the conscious experience that I have of seeing a chair is not something that can be objectively discussed. This seems to be a classic case of form without content, sort of like the symbolic logic that logical positivists were so fond of, or the analytic - synthetic dichotomy.

I have read a couple of essays from A. J. Ayer's anthology Logical Positivism recently, and I would like to chew on the ideas presented in these essays in order to figure out exactly what points of similarity and difference there are between logical positivism and Objectivism. I think this will be useful for my understanding of the history of philosophy, partly because logical positivism was one of the worldviews that Ayn Rand was reacting to. One of the essays I read was "Logical Atomism" by Bertrand Russell. Russell makes a lot of references to advanced mathematics and science, including special relativity, which made his essay difficult to understand at points. However, his basic meaning is fairly clear. The fundamental discipline of philosophy is logic, and one of the reasons people arrive at erroneous metaphysical systems is that they make logical errors. One such error that Russell discusses is confusing logical constructions with inferred entities - for example, according to Russell, the self is a logical construction out of sensory data, not an actual entity whose existence we infer from sensory data. (Other examples he gives are "mind, matter, consciousness, knowledge, experience, causality, will, time.") What actually exists, according to Russell, is not any of these logical constructions but a series of entities he calls "events," each of which exists for a very short time in a very small area of space. Russell's essay is a pretty clear example of what Peikoff calls "disintegration." Everything we know exists from common sense is disintegrated by Russell on the grounds that he regards all of these terms as scientifically unsatisfactory and imprecise. Russell seems to think that a satisfactory approach would be to derive the existence of all of these entities from a theory in theoretical physics like special relativity. This contrasts sharply with Ayn Rand's approach, which is to start with observation. We know from observation that all of the things Russell describes exist, and it is completely backwards to try to derive the existence of these entities from the existence of "events" or the entities of theoretical physics, because our knowledge of theoretical physics depends logically and chronologically on our knowledge of these everyday, common sense entities. There seems to be a difference between how Ayn Rand conceives of reduction and how the logical positivists conceive of reduction. For Ayn Rand, reduction is reduction to the given, i.e., to immediately perceivable entities. For a logical positivist, reduction is reduction to theoretical physics, which is essentially regarded as a revelation from God. The other essay I read was "The Elimination of Metaphysics Through Logical Analysis of Language" by Rudolf Carnap, but I think I've written enough for a single thread already, so I'll leave it here.

There is a recent movement in Hume scholarship that asserts that Hume isn't skeptical about things like physical objects or causality, he's just saying that we acquire our idea of physical objects or causality by means of a generally unreliable faculty that he variously calls "habit, instinct, or custom" rather than by reason. According to this interpretation, he's dead certain that these things exist, we just don't know that they exist rationally. So, if that interpretation is correct, then the view that human knowledge is limited would originate more from Kant. If you want to look into this interpretation of Hume more, the introduction to the Cambridge Companion to Hume explains it in detail.

I wish Peikoff would make his history of philosophy lectures into a book. I would love to see what he has to say but I don't like listening to audio lectures.

This sort of sounds like Spinoza. Spinoza thought that God was the only thing that existed and that all of the things we perceive are just different "modes" of God, i.e., different ways in which God appears to us. Spinoza's view on perception is also relevant here. He thought that everything exists under two attributes, the attribute of thought and the attribute of extension. So, when you have a thought, that thought is identical to a physical state of your brain - it just appears to you under the attribute of thought rather than the attribute of extension. He would say that physical things like chairs also exist under the attribute of thought, but we are only aware of them under the attribute of extension. Spinoza would say that sensory perception is not knowledge, because when you perceive something, that is just a state of your brain appearing to you under the attribute of thought. When I perceive a tree, for Spinoza, that perception is just the state of my brain, but presented to me as a thought. So, sensory perception isn't really knowledge about the world, it's just introspection, basically. What Spinoza did think was knowledge was ironclad logical deduction from what he thought were our a priori ideas. We have these ideas because we are made of matter, matter obeys certain laws, and everything under the attribute of extension also exists under the attribute of thought, so those laws appear to us under the attribute of thought as a priori ideas in our minds. We know them with certainty, and we can deduce things from them that also count as knowledge with certainty. As a result, Spinoza doesn't really even have an epistemology in the usual sense. If you think the only form of knowledge is ironclad deduction, then you don't need criteria for evaluating knowledge - either it's a crystal clear logical deduction or it's not. The way he put this is "truth is its own criterion," which means that we know something is knowledge just by looking at it or its proof. Anyway, I just thought this seemed relevant to the "first person" type view being discussed in this thread and the assumptions underlying that view. I should also mention that Spinoza is often thought to be simply a more consistent and explicit version of Descartes.

To add a potentially helpful clarification, philosophers usually use the term "modern philosophy" to refer to roughly the period between Descartes and Kant, and "contemporary philosophy" to refer to all of the philosophy being done right now.

I have taken a class on epistemology in an academic setting, so I can offer some relevant testimony. When we started the chapter on perception, the professor explained what direct realism was and then said "I don't think anyone here would be attracted to a view like that, right?" Everyone said no (I didn't respond, because I'm usually fairly reluctant to speak up in class and I wasn't in any position to defend direct realism against a whole class of philosophy majors), with one student saying "not if we're taking a class and reading a two hundred page book!" This is the approach that academic philosophy takes toward the view that we directly perceive reality, in my experience. It's seen as something only a naive person would believe. Edit: I should add that direct realism is not completely dead in contemporary philosophy. There are philosophers who have defended it recently, like Jonathan Lowe.