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Understanding Language
Version 1.002 2020-04-16
Version 1.001 2015-11-12
- Author:
- Richard Weyhrauch (IBUKI)
- Note:
- This is one of the many original personal documents written by Richard Weyhrauch and hosted by IBUKI at rww.ibuki.com. This document is not in the public domain. Richard Weyhrauch holds the copyright and permission to reprint this document must get his permission in writing. This document was written while he was employed by IBUKI but on his own time at his own expense.
Abstract
This document is a manifesto. It doesn't necessarily credit or understand what has come before. Its purpose is to describe my ideas about how language works and how these ideas contribute to the goal of building a computer system that can have ordinary language conversations with us.
It starts with the undeniable reality that, like computers, our heads are finite structures that have finite extent in three space. The implication of this simple observation is that our 'theory' can only use finite (data) structures. This eliminates almost all traditional set theoretic based theories of how language works. Our goal is to articulate ideas that can be used as a blueprint for the implementation of computer systems that understand English. We leave to other papers how this understander might, in practice, be built.
Contents
Introduction
"The purpose of Language is to communicate our thoughts"
John Horne Tooke, "The Diversions of Purley" (1857)
Exploring the consequences of Horne Tooke's remark is the starting place of this inquiry. It mentions five notions: 'purpose', 'language', 'communicate' 'our', and 'thoughts' and suggests the questions: "What is a 'language?", importantly - "What is a 'thought'?", and "What did he mean by 'our'?". I do not deal with how we 'communicated' our thoughts or what he menat by 'purpose'. For the medium of communication this essay restricts itself to text (or transcribed speech). For the purposes of this discussion, we take 'purpose' to mean "the rational for using 'language'", and leave it at that.
Our goal is to explore ideas about language that will be is useful in building humanmade/computer artifacts that can have thoughts and whose conversational abilities facilitate the comunication these thoughts through text.
What is a 'thought'?
We imagine that the building blocks of thinking are our mental images of things and that these are manipulated by mental acts. Mental images are not pictures, but are structures in our head that contain the information about something. This could be the mental image of something abstract like the idea of a dog or the mental image of something concrete, like Fido my pet dog. These notions are discussed in [****].
What is 'language'?
Language, then, is just a way of conveying these 'thoughts' (mental images) to either ourselves or others. Language is not the only way we might do this. For example, we might use art or music or non-verbal gestures. We do not imagine that conversation is limited to spoken language text but comes in many forms.We do not, however, distinguish (for the purposes of this note) between spoken (audio) and written language (texts). This distinction has many consequenses for understanding, but the details are not important here (see [****] ).
What is Meaning?
It is often imagined that sentences have 'meaning'. My understanding is
that the sentences themselves do not have meaning but
The meaning of a sentence is the effect/change it has in the head of a
hearer
There are several things to notice about this definition. First is the explicit mention of 'a hearer'. Fernando Flores pointed out to me that there is a difference between 'data' (from the latin 'do' - to give) which refers to what is given and 'capta' (from the latin 'capto' - to get or capture) meaning what is recieved. The former can be thought of as what a speaker says, the latter what a listener hears. Our definition of meaning focuses on 'capta' not 'data'. The point is clear. What matters, when a sentence is uttered, is not just the expectations of the speaker but rather how the hearer interpretes the utterance.
This is, of course, one of the main reasons people lie. Not because they intend to be deceptive, but rather they have some idea what the listener will hear and they adjust what they say to make their point. In the trivalist case an English speaker visiting Germany might try to express their desires in German, thus making it more likely they are saying something meaningful. One takeaway from John Searle's famous 'Chinese room' paper, is that for English only speakers, there is no meaning in a Chinese sentence. In my mind this is a simple direct consequence of my definition.
Second, a sentence may have different 'meaning' for different hearers. It is everyday folklore that there can be misunderstandings during conversations. Again this is a simple direct consequence of my definition. Furthermore, much of natural language is about how, in a particular conversation, the participants are to understand the words being used.
It is often remarked that the 'context' of the conversation matters. The 'meaning' of the word 'batter' will likely be different in the kitchen than at the ball park. This is right, but it needs to be understood that the 'context' itself is an aspect of the understanding of the hearer - if we are discussing baseball (or cricket) in the kitchen, that awareness is embodied in the participants, not in the sentences themselves.
All this adds up to the fact that scouring over a sentence for its 'meaning' without thinking about how it effects its hearer is hopeless.
The idea that a sentence has 'meaning' independent of its effect on a hearer leads to the idea that there is an arbitor of meaning that is outside all the participants in a conversation. I reject this and suggest instead that the notion of 'common knowledge' simply means that an individual believes that the mention of some notion in a sentence will be interpreted by most hearers in a way that is compatable with the speakers idea of the notion. Will a speaker make life or death decisions bassed on this belief? Of course not. No reasonable person believes that 'common knowledge' is absolute. They know from an early age the difference between data and capta. This is common sense justification for the above definition of meaning.
------------------------------------------------------------------------------ A long time ago I taught a course called 'Philosophy and Aritficial Intelligence' and I used to tell this story. "Suppose you are on a long drive and you get thirsty and you pull over to a roadhouse only to discover that its actually a neighborhood biker bar. As you enter you notice that the only people in the bar are very tough and strong looking men who, independent of their actual personalities, are intimidating to you by their very looks. Unfortunately, you are extremely thirsty and you decide to suppress your fears and buy a drink anyway. So you go up to the bar and happen to stand next to a very mean looking leather clad person. They take one look at you and say "What's the sum of 2 plus 2?" Here's the deal. If you hesitate for even a micro-second wondering what he 'ment', then you have doubts about the meaning of sentences even when they refer to the prima facie most basic 'analytic' truth. Either the answer is 4, without hesitation because it's shared 'common knowledge' about arithmetic (in philosophy - analytic) or if you hesitate for just an instant your faith in the external validity of arithmetic is broken. If 'common knowledge' is really true for everyone then there is no need to wonder what the person at the bar 'meant'. ------------------------------------------------------------------------------
The attempt to find the 'meaning' of a sentence outside the head of a listener is the root cause of endless difficulties in the traditional philosophy of language. Consider the debates about direct vs indirect speech acts. The issue here is whether we should accept the literal 'meaning' of a spoken sentence or instead attribute a contextual meaning to it. This boils down to - is its meaning some abstract situation independent idea (wouldn't it be nice) or, once again, is it somehow contextually defined. My definition of 'meaning' implies that all speech acts are indirect and that it is only accidental if some sentence can be thought of as having a 'direct' (i.e., a context independent) meaning.
A similiar discussion could be had about the distinction between 'de re' and 'de dicto' utterances. My definition implies that there are no 'de re' meanings but all phrases must be thought of as 'de dicto'.
Consider the sentence "John is in New Mexico" which is 'true' now but may be 'false' at some later time. Do we imagine that the 'truth' of this 'fact' has a structural differences in our heads. If it does then it would have the wierd consequence that remotely occurring events could change the physical structure of our head, i.e., since their meaning 'changes' our heads would change. John McCarthy worried about this in his discussions of what he called the 'frame problem' and how you would cope with such issues. In all the above cases, the root of the problem is the assumtion that meaning is independent of an individual and the judgement of 'truth' is not mediated by some agent. My definition rejects both these ideas.
------------------------------------------------------------------------------- Early philosophy, up to the scolastics,Here I feel the urge to discuss the idea of 'God' as aand . it may be int -------------------------------------------------------------------------------
Understand what is heard
The above discussion refocuses our attenton from trying to understand what a sentence means to trying to determine how a hearer inteprets what they hear. I believe this shift in perspective opens up a pathway both for natural language understanding and a blueprint for building a computer system that understands and can discuss its environment.