Identity judgments are, from a logical as well as, possibly, a psychological perspective, the most fundamental conceptualizations. This is our topic.
This topic is fundamental [click here for more about something’s being fundamental], but it is also important. Why?
It is important with respect to what I think of as “self making.” Self making involves making those identity (sameness) judgments regarding whether or not something is included in our self concepts (“this is me” or “it’s false that this is me”).
It is important to get clear about these fundamental judgments before using them to discuss obviously important topics such as self making. The only other alternative would be simply to take them for granted, but that alternative would infect the subsequent discussion with unnecessary uncertainty.
The importance of this topic is shown by the prevalence in language of inflected forms of the verb ‘(to) be.’ Just try to imagine making conceptualizations without them!
There’s disagreement about how many different kinds of uses there are of “is” (and related words). However, there seems agreement that there are at least these five:
The “is” of (both kinds of) identity judgments such as “this thing is itself” or “the morning star is the evening star.”
The “is” of existence such as “God is.”
(In ordinary English, this usage is infrequent because we happen to have the option to use instead some form of ‘(to) exist’ (“God exists”), “real” (“God is real”), or one of the special locutions “there is” or “there are.” Such linguistic options simply did not exist in early Indo-European – or even in classical Greek. These accidental facts about English have no philosophical importance.)
The “is” of predication such as “Socrates is white.” Noun-adjective predication asserts that an individual exemplifies a quality.
The “is” of class membership such as “Socrates is a human.” Noun-noun predication asserts than an individual is a member of a certain class.
The “is” of truth such as “It is” when used to assert that some judgment is true.
Let’s focus on just the first of these five.
There are two kinds of identity judgments: “formal” ones have the logical form “a is a” and “material” ones have the logical form “a is b.”
Since everything is what it is and not something else and since there’s no disagreement about that, let’s here focus only on the material ones. Except for occurrences in some logical or mathematical contexts, formal ones are almost never found. Why would they be? They are simply taken for granted. When was the last time you said something like “This stone is this stone”?
An object or thing is anything singleoutable. To single something out is simply to pick it out as an object of attention. (In particular, it is not to conceptualize it, in other words, to sort it into a certain category. To single an object (x) out is not to identify it [x is F or x is an F where F stands for some concept].) Singling an object out is a necessary but not a sufficient condition of identifying it. In other words, it’s logically impossible to apply concepts without first singling out whatever you are to applying them to.
A concept is a principle of classification. We use concepts to sort objects, to do intellectual work. Judgments of predication and class membership are obviously classificatory.
Is [material] identity a concept? Are identity judgments classificatory? Do we use them to sort objects?
If so, some pairs of objects are single entities (if the identity judgment is true) and some pairs are not (if the identity judgment is false).
The objects that are the subject matter of [material] identity judgments appear distinct. There’s no disagreement about that.
If they really are distinct, the identity judgments in question are false. If it is false that they really are distinct, the identity judgments in question are true.
For example, is the morning star really the evening star? The two objects certainly appear to be different by appearing at different times in different locations. Once it was discovered that “they” were both the planet Venus, we began to classify them as (one and) the same. So, in this case, two objects are really just one entity. The appearance of “their” being distinct was misleading.
Of course, it can also turn out the other way as well. If the morning star had turned out to be a different astronomical body than the evening star, then we would have concluded that the appearance of their being two distinct objects was not misleading because they are not one entity.
(The concept of complete qualitative identity, which is the concept of indiscernibility [for more on this concept, click here], is not the concept of numerical identity, which is the subject of this post.)
So, identity judgments are classificatory. They are useful. They certainly do help us understand the world. The alternative, that they are useless, is absurd.
Here’s a really important point: once we decide that a is b, we would never assert that a has a quality that b lacks. Once we make the identity judgment that they are the same or identical, we will enforce “their” indiscernibility (by the principle of the indiscernibility of identicals). (Butchvarov emphasizes this and seems to have been the first to realize it.)
In other words, because an entity can only be the same as itself, once we assert that what appear to be two objects are really one entity, we will see to it that an entity is never thought of as different from itself.
Please begin to consider how important this point is when you apply it to making your self concept. Once you decide that you are identical with something, nothing could budge you off that position. Therefore, if we make incorrect or unwise identity judgments about ourselves, we can really get into trouble.
[For more on identity judgments, there are clear introductory discussions in my The Concept of Existence and The Fundamental Ideas. There is an original and more comprehensive, advanced discussion in Panayot Butchvarov’s Being Qua Being.]