Nature creates similarities. One need only think of mimicry. The highest capacity for producing similarities, however, is man’s. His gift of seeing resemblances is nothing other than a rudiment of the powerful compulsion in former times to become and behave like something else. Perhaps there is none of his higher functions in which his mimetic faculty does not play a decisive role.
--- Walter Benjamin, "On the Mimetic Faculty" 1933
The term mimesis is derived from the Greek mimesis,
meaning to imitate . The OED defines mimesis
as "a figure of speech, whereby the words or actions of another are imitated" and "the
deliberate imitation of the behavior of one group of people by another
as a factor in social change" . Mimicry
is defined as "the action, practice, or art of mimicking or closely imitating ... the
manner, gesture, speech, or mode of actions
and persons, or the superficial characteristics of a thing" . Both
terms are generally used to denote the imitation or representation of nature,
especially in aesthetics (primarily literary and artistic media).
Within Western traditions of aesthetic thought, the concepts of imitation and mimesis have been central to attempts to theorize the essence of artistic expression, the characteristics that distinguish works of art from other phenomena, and the myriad of ways in which we experience and respond to works of art. In most cases, mimesis is defined as having two primary meanings - that of imitation (more specifically, the imitation of nature as object, phenomena, or process) and that of artistic representation. Mimesis is an extremely broad and theoretically elusive term that encompasses a range of possibilities for how the self-sufficient and symbolically generated world created by people can relate to any given "real", fundamental, exemplary, or significant world  (see keywords essays on simulation/simulacra, (2), and reciprocity). Mimesis is integral to the relationship between art and nature, and to the relation governing works of art themselves. Michael Taussig describes the mimetic faculty as "the nature that culture uses to create second nature, the faculty to copy, imitate, make models, explore difference, yield into and become Other. The wonder of mimesis lies in the copy drawing on the character and power of the original, to the point whereby the representation may even assume that character and that power." 
Pre-Platonic thought tends to emphasize the representational aspects of mimesis and its denotation of imitation, representation, portrayal, and/or the person who imitates or represents. Mimetic behavior was viewed as the representation of "something animate and concrete with characteristics that are similar to the characteristics to other phenomena" . Plato believed that mimesis was manifested in 'particulars' which resemble or imitate the forms from which they are derived; thus, the mimetic world (the world of representation and the phenomenological world) is inherently inferior in that it consists of imitations which will always be subordinate or subsidiary to their original . In addition to imitation, representation, and expression, mimetic activity produces appearances and illusions that affect the perception and behavior of people. In Republic , Plato views art as a mimetic imitation of an imitation (art mimes the phenomenological world which mimes an original, "real" world); artistic representation is highly suspect and corrupt in that it is thrice removed from its essence. Mimesis is positioned within the sphere of aesthetics, and the illusion produced by mimetic representation in art, literature, and music is viewed as alienating, inauthentic, deceptive, and inferior .
The relationship between art and imitation has always been a primary concern in examinations of the creative process, and in Aristotle's Poesis , the "natural" human inclination to imitate is described as "inherent in man from his earliest days; he differs from other animals in that he is the most imitative of all creatures, and he learns his earliest lessons by imitation. Also inborn in all of us is the instinct to enjoy works of imitation" . Mimesis is conceived as something that is natural to man, and the arts and media are natural expressions of human faculties. In contradiction to Plato (whose skeptical and hostile perception of mimesis and representation as mediations that we must get beyond in order to experience or attain the "real"), Aristotle views mimesis and mediation as fundamental expressions of our human experience within the world - as means of learning about nature that, through the perceptual experience, allow us to get closer to the "real". [see reality/hyperreality, (2)] Works of art are encoded in such a way that humans are not duped into believing that they are "reality", but rather recognize features from their own experience of the world within the work of art that cause the representation to seem valid and acceptable. Mimesis not only functions to re-create existing objects or elements of nature, but also beautifies, improves upon, and universalizes them. Mimesis creates a fictional world of representation in which there is no capacity for a non-mediated relationship to reality . Aristotle views mimesis as something that nature and humans have in common - that is not only embedded in the creative process, but also in the constitution of the human species.
In 17th and early 18th century conceptions of aesthetics, mimesis is bound to the imitation of (empirical and idealized) nature. Aesthetic theory emphasized the relationship of mimesis to artistic expression and began to embrace interior, emotive, and subjective images and representations. In the writings of Lessing and Rousseau, there is a turn away from the Aristotelian conception of mimesis as bound to the imitation of nature, and a move towards an assertion of individual creativity in which the productive relationship of one mimetic world to another is renounced .
In 20th century approaches to mimesis, authors such as Walter Benjamin, Adorno, Girard, and Derrida have defined mimetic activity as it relates to social practice and interpersonal relations rather than as just a rational process of making and producing models that emphasize the body, emotions, the senses, and temporality . The return to a conception of mimesis as a fundamental human property is most evident in the writings of Walter Benjamin  , who postulates that the mimetic faculty of humans is defined by representation and expression. The repression of the mimetic relation to the world, to the individual, and to others leads to a loss of "sensuous similarity" . "In this way language may be seen as the highest level of mimetic behavior and the most complete archive of non-sensuous similarity: a medium into which the earlier powers of mimetic production and comprehension have passed without residue, to the point where they have liquidated those of magic." 
Michael Taussig's discussion of mimesis in Mimesis and Alterity is centered around Walter Benjamin and Theodor Adorno's biologically determined model , in which mimesis is posited as an adaptive behavior (prior to language) that allows humans to make themselves similar to their surrounding environments through assimilation and play. Through physical and bodily acts of mimesis (i.e. the chameleon blending in with its environment, a child imitating a windmill, etc.), the distinction between the self and other becomes porous and flexible. Rather than dominating nature, mimesis as mimicry opens up a tactile experience of the world in which the Cartesian categories of subject and object are not firm, but rather malleable; paradoxically, difference is created by making oneself similar to something else by mimetic "imitation". Observing subjects thus assimilate themselves to the objective world rather than anthropomorphizing it in their own image .
Adorno's discussion of mimesis originates within a biological context in which mimicry (which mediates between the two states of life and death) is a zoological predecessor to mimesis. Animals are seen as genealogically perfecting mimicry (adaptation to their surroundings with the intent to deceive or delude their pursuer) as a means of survival. Survival, the attempt to guarantee life, is thus dependant upon the identification with something external and other, with "dead, lifeless material" . Magic constitutes a "prehistorical" or anthropological mimetic model - in which the identification with an aggressor (i.e. the witch doctor's identification with the wild animal) results in an immunization - an elimination of danger and the possibility of annihilation . Such a model of mimetic behavior is ambiguous in that "imitation might designate the production of a thinglike copy, but on the other hand, it might also refer to the activity of a subject which models itself according to a given prototype" . The manner in which mimesis is viewed as a correlative behavior in which a subject actively engages in "making oneself similar to an Other" dissociates mimesis from its definition as merely imitation .
In Adorno and Horkheimer's Dialectic of Enlightenment, mimesis (once a dominant practice) becomes a repressed presence in Western history in which one yields to nature (as opposed to the impulse of Enlightenment science which seeks to dominate nature) to the extent that the subject loses itself and sinks into the surrounding world. They argue that, in Western history, mimesis has been transformed by Enlightenment science from a dominant presence into a distorted, repressed, and hidden force. Artworks can "provide modernity with a possibility to revise or neutralize the domination of nature" .
Socialization and rationality suppress the "natural" behavior of man, and art provides a "refuge for mimetic behavior" . Aesthetic mimesis assimilates social reality without the subordination of nature such that the subject disappears in the work of art and the artwork allows for a reconciliation with nature .
Derrida uses the concept of mimesis in relation to texts - which are non-disposable doubles that always stand in relation to what has preceded them. Texts are deemed "nondisposable" and "double" in that they always refer to something that has preceded them and are thus "never the origin, never inner, never outer, but always doubled" . The mimetic text (which always begins as a double) lacks an original model and its inherent intertextuality demands deconstruction." Differénce is the principle of mimesis, a productive freedom, not the elimination of ambiguity; mimesis contributes to the profusion of images, words, thoughts, theories, and action, without itself becoming tangible" . Mimesis thus resists theory and constructs a world of illusion, appearances, aesthetics, and images in which existing worlds are appropriated, changed, and re-interpreted. Images are a part of our material existence, but also mimetically bind our experience of reality to subjectivity and connote a "sensuous experience that is beyond reference to reality" .