The word perception refers to what the body is able to perceive, that is, the information that the body is able to discern from the outside world. According to the Oxford English Dictionary, perception is “the process of becoming aware or conscious of a thing or things in general; the state of being aware; consciousness; understanding.” The process of understanding becomes a mediated experience, as it requires the use of the senses in order to process data. To be perceivable, the object must be able to be understood by the mind through the interplay of sight, sound, taste, touch and smell. To be perceived, a sensation must pass through the body through one of sensory organ, that is, the eye, ear, nose, mouth, or skin. To interpret that sensation is what is known as perception. The perceivable is that which can be interpreted by the body.
The current form of perception relates back clearly to its original Latin meaning as "the action of taking possession, apprehension with the mind or senses" . Perception is what allows us to make sense of the world through the experience of our senses and the collection of data, but the question remains of how we perceive and what it means to perceive. Furthermore, what makes an object perceivable? Are we the actors of perception or does it act upon us?
To perceive something is thus not to understand something, but rather to hold that perception as a truth. Aristotle acknowledges this in early forms of theories on perception. He states that "there are two distinctive peculiarities by reference to which we characterize the soul– (1) local movement and (2) thinking, understanding and perceiving" . Aristotle groups understanding and perception together under the common assumptions of his predecessors who, "all look upon thinking as a bodily process like perceiving, and hold that like is understood as well as perceived by like… They cannot escape the dilemma: either whatever seems is true (and there are some who accept this) or error is contact with the unlike: for that is the opposite of knowing of like by like… That perceiving and understanding are not identical is therefore obvious; for the former is universal in the animal world, the latter is found in only a small division of it" . Perception refers to the most immediate response we can create, the very use of our senses; perception itself is uninterrupted, it is the raw data that enters our minds in order to be processed through thought and action.
Thomas Reid explored these theories of immediacy and its relation to perception. "If, therefore, we attend to that act of our mind which we call the perception of an external object of sense, we shall find it in these three things: First, Some conception or notion of the object perceived; Secondly, A strong and irresistible conviction and belief of its present existence; and, Thirdly, That this conviction and belief are immediate, and not the effect of reasoning"4. An object is sensed and recognized as existing in its immediate form, creating an immediate experience of the object, because "it is not by train of reasoning and argumentation that we come to be convinced of the existence of what we perceive; we ask no argument for the existence of the object, but that we perceive it; perception commands our belief upon its own authority, and disdains to rest its authority upon any reasoning whatsoever" . Seeing is, in many ways, believing. To believe in an object, one must perceive its existence, but the perception that occurs is immediate. That is not to say, however, that all perception is always unmediated.
Once perception links with sensation, a function of the brain itself, the experience of the senses creates a link with experiences of the brain, connecting feelings to the immediate. Reid uses the example of smelling a rose. While the smell of a rose is merely a perception, it becomes a sensation when we realize that it is a good smell. Smell, in this case, becomes a medium for our sensation and pleasure, instead of existing independent of ourselves. Perception relies on the mere act of smelling, while sensation relies on the interpretation of that smell. Perception becomes merely the means in order to access a medium. While perception as itself is immediate, it is able to transcribe media in order to create stimulation in our brains.
Kant's views on perception revolve around the idea of a priori truths, or truths that do not come from experience, but rather from the brain itself. A priori truths are devoid of sensory input, but rather are the most basic and purely logical of human thought. Truths that extend from knowledge and experience are a posteriori truths. Posteriori truths require sensory input and posteriori knowledge cannot be obtained independently of the senses. 
One of the most important ideas from Kant's philosophy is the notion of how we understand space. While it is not there, we perceive it to be there and understand that it is there. Space and time are thus a priori truths, meaning we are aware of them without knowing such. "A distinction is commonly made between what is immediately known and what is merely inferred… Since we have constantly to make use of inference, and so end by becoming completely accustomed to it, we no longer take notice of this distinction, and…treat as being immediately perceived what has really only been inferred" . Inference relies on perception; Kant believes that many of the things that we take to be immediate truly are mediated and thus there cannot be true "immediate perception" .
James J. Gibson also explored the connection of the senses with sensation and perception. He writes, "But the fact is that there are two different meanings to the verb to sense, first, to detect something, and second, to have a sensation" . Perception under this model thus relates to the senses rather than the sensed. Gibson, however, does not believe that the senses are the key to perception. "The theory of information pickup requires perceptual systems, not senses" . These perceptual systems are, as Gibson describes, "active" versus the "passive" model of senses. Gibson relies on the cognitive to accept information from our surroundings. Sensation, as such, is tied directly and cannot be separated from what is perceived. While these statements may contradict earlier work in the field, they lead to important questions in the study of perception in relation to mediation: do we play an active or passive role in our perception? What makes media affect our perception? What qualities of perceivability are relevant in media?
John Dewey explores the role of perception in Art as Experience. For him, perception becomes an intermediary between the idea of the artist and its understanding. "The action and its consequences must be joined in perception. This relationship is what gives meaning; to grasp it is the objective of all intelligence" . For Dewey, art is not something that can be experienced in the passive, it does not happen, but rather it requires action. Perception in its most basic form relates to the senses and what is sensed, but beyond that, it is the interpretation of the mind. Dewey goes on to say, "Experience is limited by all the causes which interfere with perception of the relations between undergoing and doing. There may be interference because of excess on the side of doing or of excess on the side of receptivity, of undergoing. Unbalance on either side blurs the perception of relations and leaves the experience partial and distorted, with scant or false meaning" . In this sense, perception is not only what we see, nor is it what we understand to see, but it is this balance of seeing and understanding simultaneously. As Kant demonstrated, it is not enough to just experience, but rather there must be a set of underlying truths that enable our experience. "The doing or making is artistic when the perceived result is of such a nature that its qualities as perceived have controlled the question of production. The act of producing that is directed by intent to produce something that is enjoyed in the immediate experience of perceiving has qualities that a spontaneous or uncontrolled activity does not have" . Here, Dewey continues to explore the perceivability of art as its own material specificity demands. Art, in itself, is perceivable as art because it was because of the thought behind it. Aesthetic evaluations come after this initial perception: "as production must absorb into itself qualities of the product as perceived and be regulated by them, so, on the other side, seeing, hearing, tasting, become esthetic when relation to a distinct manner of activity qualifies what is perceived" . The perception of art thus requires some form of active role. This can be extended to any medium, as in order to understand a medium, we must use perception as the intermediary, which in itself is immediate, but connects our understanding.
The medium, in this case, because the "perceptible form" of an idea for Dewey. The materials are but one aspect to any given work of art; the perception the idea in artwork constitutes the most important element of a representation, as any representation is the representation of an idea as much as it is of an image.
It is this definition of perception in relation to a work's meaning that troubled Walter Benjamin in his seminal essay "The Work of Art in the Age of Mechanical Reproduction". According to Benjamin, perception can change through history, and with that, become distorted. "During long periods of history, the mode of human sense perception changes with humanity's entire mode of existence. The manner in which human sense perception is organized, the medium in which it is accomplished, is determined not only by nature, but my historical circumstances as well" . Through the aura, Benjamin believed that objects remained at a distance, that there was something inherently mystical and special about them. Through reproduction, however, objects and images lose their aura, and thus they become too easily perceived, leaving people open to manipulation. In Benjamin's theory, the perceivability of art was dangerous, suggesting that perception in itself is something uncontrollable. Given a set of existing truths, our perception can be tampered with based upon them.
Art can thus be something that tricks our perception in a way that even reality cannot. When our senses interpret something, there is an understanding between the viewer (or the witness) and the relation to the perceived object. The subject is in control of the perception and interprets information in a way that is privy from others. Reality has a set of standards that form our perception; space and time are a fixed system which create boundaries for the realm of the possible. Art has a way of insinuating truth within its own reality, despite it coming from the imaginary. In this way, the truth of our perception can be compromised. Artists have long looked for ways to disorient the viewer and are able to do so by taking what we assume to be true based on our previous experience and altering it. M.C. Escher prints were famous for disorienting space by merging planes, while current artists like James Turrell are able to turn three-dimensional space into two-dimensional space by utilizing fields of light. What we see, hear, smell, taste and feel can all be transformed based on our pre-existing expectations.
Freud discussed ways in which perception is in sync with his triad structure of the brain: the ego, the superego and the id. Perception is something that is perceived and recognized as perceived as it passes through levels of the unconscious and the preconscious. It is in this system that we, as the subject are able to perceive. It is no one function of the brain in itself, but rather a complex system that enables us.
Perception does not represent something that is fixed or constant, but rather has elements that are fixed in a system of changing elements. There is an immediacy to what we perceive, but what we perceive is rarely unmediated. Our experiences and cultural establishments influence our thoughts, but without them, we would have no option of the attempt at understanding. It appears as though perception is an amalgamation of the conscious and the unconscious, an active and a passive role. Objects have the ability to affect, but with that, disorient as well. Perception is not a truth but rather a belief that becomes mediated understanding.