Ø An ideational theory says that the meaning of a concept lies in how we use it in our language. A dictionary definition would be one part of an ideational definition, for example. Examples of standard and nonstandard uses of the term would also count. Elaborations of the concept in literature or science or philosophy would be part of the definition.
Ø A referential theory says that the meaning of a concept is the thing in the world that it talks about. We find the referential meaning by seeing what extralinguistic objects the word is used to discuss.
Consider the old story about the wise men all of whom touched a different part of the elephant and none of whom could see the whole. One describes elephant as if it were a leg, another as if it were a trunk, yet another as if it were an ear (I’ll stop here). They each would have a different concept of an elephant according to an ideational theory. They would each give you a different explanation of what an elephant is. But on a referential theory, each is referring to an elephant and so their concept of elephant is the same. On the ideational theory when each of them uses the word “elephant” he or she means something different by it. On the referential theory they all mean the same thing, i.e. that thing in the world that they were touching.
Criteria are beliefs that one must hold in order to correctly understand and use a concept. So one of the criteria for understanding the concept of a “cloud” is: “A cloud is not made of iron.” So anyone who said to you, “You know if I just had a big enough magnet I could bring that cloud down to earth” doesn’t understand the meaning of “cloud.”
What is the difference between "strict" and "vague" criteria?
The idea of “strict criteria” is that for any concept a set of beliefs can be identified all of which must be believed to understand the concept correctly. The “vague” or “loose” criterial idea is that it is usually not possible to identify strict criteria so that instead one accepts that someone understands a concept if s/he believes most of the criterial beliefs.
Pick a concept and give criteria for its correct use:
“Justice”: See Rawls’ A Theory of Justice (in-joke)
“sidewalk”: A sidewalk is:
Ø Is made of concrete, asphalt or other hard smooth artificial material (not dirt: if dirt, it’s a “path”; not liquid: if liquid it’s a “canal”)
Ø Is designed to allow people to walk from one place to another
Ø Is roughly level with the ground, not elevated
Ø Doesn’t melt in the rain
Ø Will cause many things dropped on it to bounce or break.
Ø Will not suddenly open up and let you drop through all the way to the center of the Earth
Ø Is not the back of some huge sleeping creature
Ø Doesn’t move from place to place overnight
Ø Witchcraft in 1500 and now
Ø Acids in Sir Humphry Davy’s time and now
Witchcraft:On an ideational view, we look at how witchcraft has been defined and discussed. The major difference between then and now is not so much that we conceive of witchcraft differently as that we no longer believe witches (in this sense) exist. So the ideational theory would say that the concept of witchcraft has the same meaning then and now. The referential view holds that the meaning is defined by the objects in the world that “witchcraft” picks out. Since there were no witches then and are no witches now (Wiccans excepted as being a different kind of witch), the concept has the same meaning then as now. (Note the problem with the referential theory in this crude form: since “unicorn” and “witch” both refer to the same thing, i.e. nothing, they should mean the same. This doesn’t seem quite right. I refer you to my colleagues in the philosophy of language and to Bertrand Russell’s “On Denoting” (for starters) if you wish to pursue this any further.)
Acids: What Humphry Davy and his scientific colleagues thought acids were is not what contemporary chemists think acids are. Their talk about acids, their theoretical definitions of what an acid was, were significantly different from our modern ideas of what an acid is: a proton-donor. Davy had no conception of atoms or atomic structure or protons or electrons, so he couldn’t have had an idea of acid that incorporated anything like these ideas. So on an ideational account, the meaning of “acid” has changed from Davy’s time to ours. But if we look at the substances he did his experiments on, we find that they are more or less the very same substances that we call acids today. If you put out a large set of samples of different substances, Davy and a modern chemist would pick out the same ones as acids. So on a referential view, the meaning of acid has not changed. Davy was talking about the very same thing as we are even though his ideas about what acids were were different from ours.