To understand the significance of common sense realism and ultimately the linguistic
    arguments used to support it, we need to briefly talk about two kinds of facts.

There are facts that are based upon experience, and these facts, according to Wall, "...tell
    us only of appearances and not reality."  These would include facts of about perception
    and what is immediately given in experience or what we have experienced.

There are also facts about language. Wall notes, "As it turns out, thoughts or beliefs can only
    be understood by means of the language we use to express them."(223) 'Understood' in this
    sentence is ambiguous. Some think we can understand our own personal perspective
    without language, such as the vividness of a beautiful sunset. He is gesturing against that
    idea of a personal experience, but I think 'understood' here is far more public. My
    thoughts and beliefs can only be understood by you if we have language of some kind.
    I think he is making the intersubjective claim here to set up common sense realism and
    the linguistic arguments.

The following quote from Wall is very important to understanding the linguistic arguments.
    He states, "Let us think of knowledge as a set of symbols within our minds, symbols that
    are supposed to represent reality. These symbols are of various sorts, such as individual
    sense data like sounds, tastes, and odors (which represent sensory properties); perceptions
    (which represent individual objects); concepts (which represents kinds of objects); beliefs
    (which represent facts about these objects); and systems of beliefs (which represent
    general ways of understanding our experience). If concepts, beliefs, and systems of
    are what we use to understand our experience, and if they may be understood only by
    means of the languages that we use to express them, then language itself also may be
    seen as a way to represent the world." (224)

Translation: Wall is saying that the very idea of language already contains a particular
    metaphysic. Put another way, language represents the world, as the world. For
    example, we know that the word 'chair' represents a particular thing, but also that
    thing is actually in the world as a part of it.

One final idea. Wall says, "Languages used to describe the world express ways of
    understanding that are supposed to represent the world. This fact about language
    that it is a shared, public way to represent reality is going to be important for
    understanding each of our possible solutions."

The Egocentric Predicament. Two assumptions: 1) To know the world is to mentally represent
    it, and 2) We know only our own direct representations. Remember the internalist picture
    of representation for 1, and the incorrigibility thesis for the second. We know only our
    own representations and we cannot be wrong about them.

The Egocentric Perspective is defined as: a) we cannot know the nature of reality because our
    knowledge of the world is limited to our representations, and b) we have no way of knowing
    if how  we represent reality accurately reflects its true nature. (229) We might think of the
    egocentric perspective as an extreme form of Nagel's personal or subjective
    perspective. Nagel might allow (a) but (b) definitely goes beyond what Nagel would
    agree to through his notion of objective detachment.

Be sure to notice the differences in terminology with respect to 'predicament' and
    'perspective.' They are not the same thing.

The Linguistic Turn. The linguistic turn is made by contemporary philosophers who have
    turned away from thinking about knowledge as the private contents of our minds. Instead
    they focus upon what gets expressed in language, as a public vehicle of thought. (225-226)

The Linguistic Arguments

The linguistic arguments are all going to attack the egocentric perspective. To reiterate,
    the egocentric perspective is defined as:
    a) we cannot know the nature of reality because our knowledge of the world is limited
        to our representations, and
    b) we have no way of knowing if how we represent reality accurately reflects its true
        nature.

So, either (a) or (b) must dealt with by the linguistic arguments.

A Preliminary

Wall sets this section up very well. In the short section on "Ordinary-Language Philosophy
    and Empiricism" he draws out some similarities and differences with classical empiricists
    like Hume.

    Similar--
    i) Believe the knowledge of the world arises from experience. Everything we know about
        the world, we learn through experience.
    ii) They are opposed to revisionistic metaphysics. What this means is that any
        metaphysical system that revises our ordinary understanding of the world is
        misguided.

    Dissimilar--
    iii) OLP takes knowledge to be public and empiricism takes it to be private.
    iv) OLP take public objects as being perceived directly and empiricism takes
            private sensations as being directly perceived.

I will add the detail and explain the following arguments in class. You will want to have read
    these in Wall book to further increase your understanding of the relevant issues.

The First Linguistic Argument: Knowledge is Public

General Idea: "Language is a social product that embodies not just words but also what the
    words mean--the concepts or ideas they express. In acquiring these ways of thinking, we
    have help from the entire community of language users. Like apprentices in a trade who
    acquire from others the skills that a community of workers has developed over generations,
    for us to acquire ordinary language is to learn from others how to understand and interpret
    our experience as they have done for centuries." (232)

Against the Egocentric Perspective: "Because the concepts embedded in ordinary language
    have been developed as a shared enterprise, the must be developed in a public way, in
    a way that uses them to understand what may be observed by all. Because of this, they
    are designed to correspond to the way the world really is, not just how we individually
    think it is. That is, how we name and describe public objects reveals how things are. If
    it did not fit reality, language would fail to communicate accurately, and thus, would
    need to be changed so that it did." (232)

First Linguistic Argument

LA1-If we represent the world with a publicly acquired set of ideas, then there is no reason
    to believe that they do not accurately represent reality.
LA2-We do represent the world with a publicly acquired set of ideas.
CLA--Therefore, there is no reason to believe that they do not represent reality.

The Second Linguistic Argument: Austin

General Idea:  "When we examine how we ordinarily speak about perception, however,
    we find that the objects of perception are described as public objects, as things that
    exist independently of our private perceptions. What we see, hear, taste, smell and
    touch are described as things--and as things as they really are. They are not described
    as subjective sensations that reveal how things appear to us." (233)

Against the Egocentric Perspective: "Austin's careful analysis of language points out that once
    again the egocentric perspective has things backward. The very notion of a private sensory
    experience is itself derived from our knowledge of public objects....So our knowledge of
    private objects, of how things appear to us, presupposes a knowledge of public objects,
    of how things really are." (233)

Second Linguistic Argument

SLA1--If our ordinary language is a public-object language, then we do not perceive private
    sense data.
SLA2--If we do not perceive private sense data, then there is no problem of whether or not
    sense data represent public objects.
CSLA--Therefore, if our ordinary language is a public object language, then there is no
    problem of whether or not sense data represent public objects.

The Third Linguistic Argument: Wittgenstein

General Idea: Wittgenstein is arguing against the possibility of a private language. A private
    language is one that only one person would have. "Now Wittgenstein's explanation
    for why a private language is impossible must be clearly stated. It is impossible because
    it cannot contain semantic rules. Private languages contain no semantic rules because
    in a language used to refer to private objects, objects capable of being known only to
    one person, there can be no public criteria that govern consistent word-thing relationships.
    Who knows? What I call a sensation of pain, you may call a sensation of joy. What I call
    a sensation of doglike barking sound, you may refer to it as the sweet sound of a bird's
    song." (235)

Against the Egocentric Perspective: "It must be abandoned because it assumes that we can
    speak meaningfully about private perceptions in the absence of public criteria. To abandon
    the egocentric perspective is to give up the view that what we know are private mental
    states. Once this claim is rejected, then so is the problem that follows from it, namely, the
    impossibility of knowing if such states accurately represent the world of public objects."(236)

Following Malcolm Budd, the private language argument has four primary theses:

(PLA1) if language is to be a means of communication then there must be an agreement in
    judgments;
(PLA2) it is the way that we use a word that determines its meaning;
(PLA3) words for sensations are concatenated with behavior; and
(PLA4) a person does not identify their sensations via a criteria.

If you violate PLA1--PLA4, you are supporting a private language.

The Fourth Linguistic Argument: Strawson

General Idea: "Strawson claims that any language that is used to refer to and describe the
    world must implicitly contain a general idea of what the world is like, a general
    conception of reality that all users of that language share. Such a general concept does
    not readily show itself to all language uses, but it 'lies submerged,' as he puts it, and must
    be uncovered. The concept of reality contained in ordinary language is basically the one
    defended by commonsense realism and the one that we all accept in our daily lives. This
    is the idea that the world consists of persons and material objects with all their primary
    and secondary qualities, that these objects are related to each other in space and time,
    and that they are also causally related." (238)

    Conceptual Framework--a shared general idea about the nature of reality.

    "All languages implicitly contain a conception of the reality that they talk about, a
    conceptual framework."

Against the Egocentric Perspective: Reality is built into language. Strawson would definitely
    go against (b) by showing that we have no reason to doubt that we know the world as it
    is given our conceptual scheme and language. We learn about the world through language
    and to claim that we may not know what it is like, is to dismiss what language has done
    for you up to this point. Why would you start doubting that 'chair' doesn't describe the very
    thing you were raised believing it to be?

Fourth Linguistic Argument

FLA1-If our ordinary conceptual framework is epistemologically basic, then it is
    metaphysically basic.
FLA2-Our ordinary conceptual framework is epistemologically basic.
CFLA--Therefore, our ordinary conceptual framework is metaphysically basic.