Philosophy; Kaplan, Kripkenstein

1. David Kaplan makes several statements regarding the use of demonstratives. Primarily he claims that there are two obvious principles that govern the use of what he calls demonstratives. Furthermore Kaplan says that the two obvious principles of demonstratives also yield two different kinds of meaning. To start the discussion I will speak of the two obvious principles of demonstratives.
Kaplan’s theory of demonstratives is based on what he claims to be two obvious principles. These principles are as follows:
Principle 1 The referent of a pure indexical depends on the context, and the referent of a demonstrative depends on the associated demonstration.
Principle 2 Indexicals, pure and demonstrative alike, are directly referential.
At face value these principles appear to be conflicting. To alleviate conflict I will first discuss principle 1. However, before discussing the details of the principles we must first understand how Kaplan uses the words demonstrative and indexical. Kaplan places demonstratives into two classes as follows:
1) (Pure) demonstratives require a demonstration to complete its function. Demonstratives include words like he, she, it, this, etc.
2) (Pure) indexicals do not require a de

Regarding Kaplan’s 2 notions of meaning it appears as though John Perry’s paper “The Problem of the Essential Indexical” maps on to content and character as expressed by Kaplan. Perry’s problem with the essential indexical is presented in the following manner. We take the case of a shopper (Perry) pushing a grocery cart with groceries in the cart. While shopping he (Perry) notices a trail of sugar, he decides to follow the trail of sugar so that he may tell the guy that he (the other shopper) has a torn sack of sugar. After following the trail of sugar it dawned on him (Perry) that he (Perry) was the one with the torn sack of sugar. At the outset he (Perry) believed that the shopper with the torn sack was making a mess. As Perry came to believe that he was the one making the mess he also experienced a change in behavior. The fundamental question is what happened when Perry came to believe ‘I am making a mess’.

2. In the Kripkenstein paper, On Rules and Private Language a problem is presented about following rules. The problem states that upon arriving at a set of integers such as ’68 + 57’ that we have never added it is natural to say that the answer is ‘125’. The person who says the answer is ‘125’ claims to be following the rules for addition (‘+’ and ‘plus’) and as a matter of past experience is able to correctly add the previous set of numbers. The problem the sceptic presents is interesting and seemingly logical. The sceptic says that there is another function called ‘quss’ that functions exactly like ‘plus’ except when you arrive at a number you have never previously added the answer is five. The definition of quss is this: x quus y = x + y, if x, y < 57; otherwise, x quss y = 5. So the basic problem here is that on all the problems that I have done so far, the plus and quss functions demand the same answers and it is impossible for me to know if I am qussing or using ‘+’. According to my understanding of the problem presented, because I am unable to determine if I am using quss or plus means that language is a function of a community and is essentially meaningless. This to me seems to be true. Language as I understand it, seems to be developed on a sense of agreements made in the community under which I live. Language at its point of inception began as an agreement be