Intentionality

In his early work, Brentano thought that every intentional state must have an intentional object. If, for example, I believe that the mail carrier arrives at 11 A.M., then it seems that the object of my belief is the mail carrier. But what is the intentional object when a child believes that Santa Claus comes on Christmas Eve? There is no such person as Santa Claus, so what is the child's belief directed at? Brentano thought that to provide an intentional object in such cases, we have to postulate it inside the intentional state itself. Brentano called this mode of existence "intentional inexistence." This is an error. The statement, "Santa Claus comes on Christmas Eve" has a meaning but does not thereby succeed in referring to Santa Claus because there is no such thing to refer to; and likewise the belief that Santa Claus comes on Christmas Eve has an intentional content but does not have an intentional object. Brentano was confusing intentional content with intentional object. By definition every intentional state has an intentional content but not every intentional state has an intentional object. An intentional state has an intentional object only if something fits or satisfies the intentional content.

A second error is to suppose that there is some essential connection between intentionality with a "t" and intensionality with an "s." Intensionality with an "s" is a property of sentences by which they fail certain tests for extensionality. The most famous test is called "Leibnitz's law" or the "substitutability of identicals." If two expressions refer to the same object, then one can be substituted for the other, without loss or change of truth value. Thus, if a equals b, and a has property F, then b has property F. But for some sentences about intentional states, this law does not hold. So, for example:

1. Sam believes that Caesar crossed the Rubicon; and

2. Caesar is identical with Mark Anthony's best friend;

do not imply that:

3. Sam believes that Mark Anthony's best friend crossed the Rubicon;

because Sam might not know or might disbelieve that Caesar is Mark Anthony's best friend. The sentence about the intentional state is intensional with an "s" but it does not follow from this that the state itself is intensional with an "s." Chisholm and others have tried to make the intensionality of sentences about intentional states into a criterion of intentionality and thus make intentionality seem to be a linguistic phenomenon. But the effort failed. There are intensional sentences that do not report intentionality and reports of intentionality that are not intensional. For example, 4 is intensional but not about intentionality:

4. Necessarily, 9 is greater than 7;

5. The number of planets equals 9.

But it does not follow that:

6. Necessarily the number of planets is greater than 7.

Sentence 7 is about intentionality but is not intensional.

7. Sam saw the Eiffel Tower; and

8. The Eiffel Tower is the tallest iron structure in Paris.

do imply:

9. Sam saw the tallest iron structure in Paris;

even if Sam does not know the truth of 8.

If intensionality is not a sure test for intentionality, what then is the relation between them? Sam's belief that Caesar crossed the Rubicon represents the state of affairs that Caesar crossed the Rubicon. But the report of Sam's belief does not represent that state of affairs; rather it reports what is going on in Sam's head. The report is a representation of a representation. So the truth of the report requires that the way that Sam represents Caesar be truly reported, and hence substitution fails, for the substitution of a different representation may not truly report what is in Sam's head (Searle, 1983).