A discussion of intentionality, at least in philosophy, usually involves a reference to the work of Franz Brentano or Edmund Husserl and an accompanying description indicating that it is a philosophical term that signifies the ‘aboutness’ or "directedness" of mental states like thinking,
wishing, remembering et cetera. Of course that captures some of what "intentionality" means in philosophy and in more common discourse. The problem with the standard description is that it seems to lend significance to thoughts, and the significance of language/meaning is either merely implicit or in some sense irrelevant. Additionally, it informs a particular epistemology and metaphysics that treats linguistic acts as mere expressions of thought. Suffice it to say that the absence of the import of language and/or meaning is manifest, I think, in Brentano’s own description of intentionality in Psychology from an Empirical Standpoint:
"Every mental phenomena is characterized by what the Scholastics of the Middle Ages called the intentional (or mental) inexistence of an object, and what we might call, though not wholly unambiguously, reference to a content, direction toward an object (which is not to be understand as meaning a thing), or immanent objectivity. Every mental phenomenon includes something as object within itself, although they do not do so in the same way. In presentation, something is presented, in judgment something is affirmed or denied, in love loved, in hate hated, in desire desired and so on."
"This intentional inexistence is characteristic exclusively of mental phenomena. No physical phenomenon exhibits anything like it. We can, therefore, define mental phenomena by saying that they are those phenomena which contain an object intentionally within themselves."
Brentano’s description above, and it is taken to be the starting point for contemporary discussions of intentionality, stresses the ontological dualism between mental and physical things. Brentano tells us that what separates mental phenomena from physical phenomena is that mental phenomena are marked by intentionality. In order for a thing to be mental it has to have intentionality: it must be able to refer to something with the bizarre difficulty that the referent need not exist. This, in a nutshell, is intentional inexistence. It merely holds that a thought about p does not require that p’s referent indeed exists. After all, people have thoughts about unicorns and unicorns don’t exist. If this all seems intuitive, it largely is. However, the reason why it is has to do, as I will later explicate, more to do with linguistic convention than with ‘how mental phenomena really are’.
The second standard of Brentano’s description above is that it yields the idea that it is, in a sense, logically impossible to have a thought simpliciter: that is, whatever else a thought is, it must be a thought of something. One is reminded here of Plato’s Theaetetus in which Socrates and the young Theaetetus are struggling with the notion of false belief: how can one think falsely (if false belief is defined as thinking that which is not) given that one’s thought that p necessitates that something is thought? The relevant point is that Brentano’s characterization echoes the (somewhat) Platonic idea that one cannot have a thought without indicating or being aware of what the thought states is the case, what it represents, what it is about, or what it is in relation to. If one is thinking, one must be thinking of something, and that something is somehow related to the thinker. This second standard can be termed as the relational nature of intentionality.
Third, intentional acts are directed upon things that are not sufficiently specified by the language one uses to describe those acts. Thus if someone describes her occurent–that is, current mental state of— fear of bats in virtue of the fact that she is aware of a bat and is trembling, then it is not the case that the description is sufficient for the content of her intentional state; in effect, the descriptions "S is presently fearful of bats" and "S is aware of a bat and is trembling" are not necessarily equivalent statements since there could be other things present in S’s mind that are not described by the predicate "is fearful" , not to mention the fact that "awareness of a bat and trembling" may occur independent of "being afraid". As Grant Gillett explains, "…those things [that a mental predicate is meant to represent] are in general not adequately specified for the purpose of mental descriptions by mentioning the objects concerned."
Husserl, like Brentano, posits that consciousness is essentially intentional. But where Brentano turns to cognitive significance in his characterization of intentionality in terms of the sort of mental states that have intentional content, Husserl turns to meaning:
"Every intentional experience, thanks to its noetic phase, is noetic, it is its essential nature to harbour in itself a ‘meaning’ of some sort, it may be many meanings."
I am not certain if ‘meaning’ is used in the sense of ‘meaning to act or behave a certain way’ or if he is referring to the activity of language and the linguistic expression of intentional contents in some psychological states. That said, it is not inconsistent with either Brentano or Husserl’s description, I think, to consider the underspecified nature of linguistic expressions taken to name intentional contents.
Psychological explanations then call for an elucidation of the underspecified mental predicate: to express the meaning of experiences of cognitive significance, a theory of intentionality must elucidate how it is that a particular mental state is realized.
When these standards are put together they inform the following sort of argument (numbered 1-4):
1. If S believes that p, then it doesn’t follow that what p refers to actually exists. (intentional inexistence)
2. Q: In order for S to believe that p it must be that p represents or is about something which is related to something outside the thought or belief itself. (relational nature of intentionality) S’s belief that p must be a belief about something (i.e. the belief must have content).
3. For any relation to obtain, the objects in the relation must both exist; i.e. it’s senseless to hold that A is related to B if it is the case that A or B does not exist.
4. In order for S to believe to that p, where p need not refer to any existent object and "the belief that p" logically necessitates that p be about something, then the content of S’s belief must denote an intentional object. Thus, intentional acts or states are those that express contents that refer to some sort of object (intentional object) that may not really exist.
The conclusion that there must exist intentional objects raises a metaphysical problem: what is an intentional object and in what sense do they exist? On the one hand, it is a principle of all intentional acts (thoughts, beliefs, desires, et cetera) that what is presented as object need not actually exist. On the other hand, something must exist in order for a belief to exist, for if a belief exists it must follow that it is a belief about something (unless Socrates isn’t taken seriously). The existence of intentional objects raises a third realm of existence and seems like an ad hoc conclusion to resolve (otherwise) major metaphysical flaws. That said, the sort of metaphysical and epistemological work that this kind of characterization of intentionality yields is something to avoid, given recent developments in the philosophy of language and (to some extent) in the philosophy of mind.
Introducing intentionality in this (rather) characteristic way is, as I have hinted above, problematic. The reason I want to steer away from this sort of talk is that it masks the essential role of language in determining the intentionality of a thought, belief, proposition, expression, et cetera.
Moreover, that intentionality is described here as "the mark of the mental" is indicative of a dualistic metaphysics, one that presupposes an ontological distinction between "what is mental" and "what is physical." When I say that contemporary discussions of intentionality are not interested in this sort of dualism (although depending on what one means by dualism, certainly it could be argued that in a sense another sort of dualism exists), I mean that (in general) analytic and post-analytic accounts of intentionality either do not ascribe an ontological level to that sort of mental phenomena or are mostly reductive such that intentionality belongs to the physical. Nevertheless, it is a fact that must be appreciated: contemporary discussions of intentionality are not voiced in the interest of carving out the proper object of psychological inquiry. Brentano’s use of the term is indicative of the motivation to establish psychology as a scientific discourse in some sense analogous to physics. The same does not hold true today (though there is, in some instances, the want to treat intentionality systematically according to its logical properties in language, so there is some reverence of science) and this constitutes the second reason why my discussion of intentionality will steer clear of the traditional ontological obstacles described above.
Current work on intentionality in various philosophical circles can be assessed according to levels of explanation. What I mean by that is that the various hallmarks of intentionality, what it conditions and how it is conditioned, are related to the level of analysis in which it is assessed. That’s not to say that there is no interplay between, for instance, a teleological or causal explanation of intentionality, like one offered by Ruth Millikan, and the logical explanation offered by Roderick Chisholm. But treating these levels as somewhat autonomous has the distinct advantage of making clear the sorts of problems philosophers encounter when talking about mental representations, the capacity of the mind to be directed towards something outside of it, and the individuation of meaning. After having introduced the more or less traditional (metaphysical) construction of intentionality, I will now turn to a level-of-analysis approach in which the network of problems associated with intentionality is given proper theoretical context. The levels and the questions appropriate to them might look something like this:
Logical/Linguistic: what are the logical features of intentionality that structure their expression in linguistic acts?
Teleological/Functional: what sort of causality is involved in the intentional relation (‘internal representations’ vs. ‘what the representations are representative of’) and what is its function within a naturalistic metaphysics?
After sufficiently presenting each level of explanation via the philosophers that characterize them, I’m going to turn to Wittgenstein’s later philosophy of language in an effort to assess the scope and value of these efforts in general. Here I will use particular examples of language-games involving the meaning of psychological ascriptions and compare them to some of the more recent work involving intentionality. What I will show in using Wittgenstein’s later philosophy is that these efforts dissociate the actual contexts of use of philosophically-heavy terms like to know, to remember, to represent and thus cannot, properly said, speak to or about intentionality and all its related phenomena. Wittgenstein’s attention to the social nature of meaning in general serves as catalyst for the conclusion regarding intentionality that I submit: intentionality is social to the extent that it is senseless to theorize about it in the sort of mind-object and/or subject-object relation it is typically characterized in.
 See Franz Brentano. Psychology from an Empirical Standpoint. 1874: 88-89
 See Franz Brentano. Psychology from an Empirical Standpoint, 1874: 88-89
 Brentano describes the relational nature of intentionality as an implication of the idea that "what is characteristic of every mental activity is…the reference to something as object. In this respect, every mental activity seems to be something relational."
 For a useful description of Husserl’s understanding of mental contents and objects see Gillett, 333. Grant Gillett. Husserl, Wittgenstein and the Snark: Intentionality and Social Naturalism. Philosophy and Phenomenological Research, Vol. 57, No. 2. (Jun., 1997) pp. 331-349
 Edmond Husserl. Ideas (1962) p. 237
 At this point I also want to note that while I am aware of the proximity of Husserl’s phenomenological tradition in the development of the notion of intentionality, I am going to steer clear of it as well. However that trajectory influenced the "linguistic turn" turn in philosophy and the emphasis on linguistically realized normative aspects of intentionality is certainly very interesting, it is a topic quite outside the scope of this project.
 If it’s not already clear, most of the contemporary work I review here can be characterized as theories of mental content (or theories of intentional content). The move from the philosophical inquiring into intentionality to ‘intentional content’ reflects the practices of positivist and post-positivist accounts of meaning and language. ‘Intentional content’ more or less becomes ‘that which is specified by an ascription of a folk-psychological state’.