Intentionality is defined as a relationship between mental states of a human being and the external environment. This phenomenon determines and directs these mental states at certain objects, events, etc. It is an important element of mental experience, because intentionality directed it towards external world and gives our desires, sensations, feelings, believes certain content, certain orientation. This happens very often, because as a rule our perception, our thinking and experiencing are intentional, as we always perceive, experience something as something existed in the external world or given to us.

The notion of “intentionality” has Scholastic origin, but nowadays it was reintroduced by Franz Bernando. The philosopher determined the notion as an important feature of “physical phenomena” and pointed out that the core of it was “intentional inexistence of an object” (Chisholm, 1967).

Bernando states that almost every mental state or action has certain content, certain direction. He says that person’s desires, thoughts, feelings, sensations are directed at certain objects, events of the environment. He also declares that all these external objects and events at which the mind is directed have one common characteristic called “intentional inexistence”. Bernando means that there is no mental state that could experience intentionality without having some intentional objects. In a word, a person could not love, hate, believe, perceive, etc without having an object to be loved, hated, believed or perceived. This is an essence of Bernando’s notion “intentional inexistence”. Brentano claims that not every “physical phenomena” has its intentionality. Because he is sure that only mental states or acts can have it. Chisholm in his book “Brentano on Descriptive Psychology and the Intentional” (1967) agrees with these arguments of Brentano, explaining them in the terms of psychology. He says that when a person is eager to describe non-psychological phenomena, he does not need to use intentional words. But when a person wants to describe his emotions, feelings, desires, experience, etc, he has to include in this description intentional objects, to use intentional language.

Daniel Dennett in his book “Intentional systems” (1981) works out the concept of intentional systems whose behavior can be explained and predicted according to the system of desires, hopes, believes, etc. He challenges Bretanto’s point of view about dividing mental states from physical phenomena. Dennett thinks that it is possible to use intentional predictions not only towards human beings, but also towards mechanical objects. Such predictions are based on design stance, because designed response can be predictable; on physical stance of certain objects; on intentional stance that allow to predict according to the possession of certain information and certain goals. In such a way Dennett wants to show that intentionality can be peculiar both to man or animal and to machine. In a word, he tries to demonstrate that there can be different systems: man, machine or any creature, and to prove that their behavior can be explained and predictable with the help of examining their “desires, beliefs, goals”. Nevertheless, Dennett states that there is a feature that distinguishing conscious states of mind from other physical states. It is the richness of intentional content, but not some special and differing kind of this content. To sum it up, there should be pointed out that Dennett tried to go further in the investigation of intentionality. He presupposed that with the help of intentionality not only human’s desires, beliefs, hopes can be predicted but also those of mechanical objects.

Many researchers declare that consciousness and intentionality penetrate into mental states and define intentionality as “mental representation” which determines the direction of these states. At the same time these researchers state that sense experience demonstrates a sort of intentionality, which differs from that connected with conceptual thinking. In a word, sense experience provides a kind of content that is different from intentional content provided by judgment experience. Fred Dretske (2003) is one of these scientists. He contrasts two kinds of the intentionality according to sense-experience and judgment experience. He explains it by the fact that intentionality includes certain sense representations that can appear and develop without any learning or thinking. The content of these representations appears as a result of indication and recognition. In such a way Fred Dretske tries to prove that another kind of intetionality based on cognition understanding cannot exist without learning and cognition. Thereby he shows the distinction between the types of intentionality, separating them according to intellectual and sensory experiences.

Fred Dretske’s point of view is opposite to that of Dennett. Nevertheless both those theories have right to exist and they have common feature. Dennett and Dretske understand intentionality as a special characteristic of consciousness that should be taken into account first of all, because it is a very essential and necessary feature of mental states.

In conclusion, there should be pointed out that almost every mental state has intentionality. Because almost every thing, every object, action, event existed in the environment is directed at or represents other things, objects, actions, etc. It is quite natural, because when we love there is what to love, when we believe there is what to be believed, when we desire – to be desired, when we hate – to be hated and so on. Our feeling, sensations, desires, goals are always directed and stand for something external.

In the present work there were covered different points of view on the issue of intentionality - Brentano’s, Dennett’s and Dretske’s. But all they agree that intentionality as a relationship between mental states and the external environment is an essential and important feature of consciousness.