contemporary art in general ...". Osborne noted that contemporary art is 'post-conceptual' in a public lecture delivered in 2010. Gary Tedman has put forward a theory of a subjectless aesthetics derived from Karl Marx's concept of alienation, and Louis Althusser's antihumanism, using elements of Freud's group psychology, defining a concept of the 'aesthetic level of practice'. Gregory Loewen has suggested that the subject is key in the interaction with the aesthetic object. The work of art serves as a vehicle for the projection of the individual's identity into the world of objects, as well as being the irruptive source of much of what is uncanny in modern life. As well, art is used to memorialize individuated biographies in a manner that allows persons to imagine that they are part of something greater than themselves. Criticism The philosophy of aesthetics as a practice has been criticized by some sociologists and writers of art and society. Raymond Williams, for example, argues that there is no unique and or individual aesthetic object which can be extrapolated from the art world, but rather that there is a continuum of cultural forms and experience of which ordinary speech and experiences may signal as art. By "art" we may frame several artistic "works" or "creations" as so though this reference remains within the institution or special event which creates it and this leaves some works or other possible "art" outside of the frame work, or other interpretations such as other phenomenon which may not be considered as "art". Pierre Bourdieu disagrees with Kant's idea of the "aesthetic". He argues that Kant's "aesthetic" merely represents an experience that is the product of an elevated class habitus and scholarly leisure as opposed to other possible and equally valid "aesthetic" experiences which lay outside Kant's narrow definition. Timothy Laurie argues that theories of musical aesthetics "framed entirely in terms of appreciation, contemplation or reflection risk idealizing an implausibly unmotivated listener defined solely through musical objects, rather than seeing them as a person for whom complex intentions and motivations produce variable attractions to cultural objects and practices". See also Aesthetics of science Art and Theosophy Art periods History of aesthetics before the 20th century Medieval aesthetics Esthesic and poietic Mise en scène Theological aesthetics Theory of art References Further reading Mario Perniola, 20th Century Aesthetics. Towards A Theory of Feeling, translated by Massimo Verdicchio, London, New Delhi, New York, Sydney: