What is the purpose of art? An comprehensive answer to this question would involve more than just an account of the institutional reality of contemporary art. It would address the historical process of self-definition through which art got where it is now, tracing the various moments of its self- imposed split from craft: as propaganda, decoration, or entertainment, and examining the gradual reinforcement then sudden collapse of the barriers between mediums: the dialectic of concrete figure and abstract form in painting and sculpture, the subsequent rise of performance and installation, and the eventual emergence of the exhibition as its own medium under the banner of ‘relational aesthetics’. It would also explore the tumultuous relationship with literature, music, drama, cinema, and other institutionalised practices that covet the title of arts.

I will have something to say about elements of this history, and what it tells us about the nature of art, but a truly comprehensive answer to the difficult question will have to wait for another time. Instead, I will focus on the ideal relationship between the production and consumption of the art work, which is to say, on the circuit that the genuine work forms between the artist and the beholder, from brain to brain.

There are two opposing ways of understanding the relation between artist and beholder that have dominated thinking about art since the middle of the last century: the aesthetic model and the semantic model. The central difference between these two models lies on the side of consumption, in the effect that the work is supposed to have upon the beholder: in the aesthetic model, the work is supposed to stimulate a sensory or emotional response, whereas in the semantic model, the work is supposed to communicate a message of some kind. The consequence of this is a difference on the side of production, in the nature of the artist’s creative activity: in the aesthetic model, the artist’s mind is focused on the design of an effective form, whereas in the semantic model, the artist’s mind is focused on the articulation of a significant content.

It’s important to understand that these general positions hide a great deal of potential variation, with many otherwise opposed theories falling on the same side of the divide. The aesthetic model includes the perennial view of aesthetic taste as an immediate source of sensory pleasure, alongside the formalist concern with the technicalities of aesthetic composition, and the myriad champions of intensities of feeling beyond mere pleasure, from sublime awe to visceral disgust. The semantic model includes the traditional view of artistic value as an immediate source of religious, moral, or even political understanding, alongside the anti-formalist concern with the artist’s subjective expression, and the originators, defenders, and inheritors of the tradition of conceptual art.

It’s equally important to understand that most variants on these positions do not deny that art can both stimulate and communicate, but rather that they subordinate one (as means) to the other (as end). For example, the Church commissioned aesthetically skilled painters to communicate religious messages, precisely because the rhetorical effectiveness of these messages depended upon the power of their compositions to stimulate sensory and emotional responses. The converse might be said for certain cases of shock art and kitsch, in which the work is made to communicate a message for emotive effect, such as a frisson produced by breaking taboo, or nostalgia induced by invoking cliché. These modes of subordination are ways of configuring the relation between form and content, and although they may not account for every possible configuration to be found in the realm of genuine art, they do allow advocates of each model to explain many of their opponent’s preferred examples in their own terms.

Finally, this focus on form or content doesn’t prevent either model from incorporating a corresponding concern with matter. It’s all too easy to explain the design of form as isolated from the matter it is imposed on (excessive hylomorphism), or the articulation of content as independent of the medium in which it is expressed (excessive idealism). In each case, the temptation is to see the essence of the art work, be it form or content, as an idea contained in the artist’s mind, and its matter or medium as something inessential, which contributes nothing to the idea but its realisation. However, it’s entirely possible for either model to treat the matter upon which the artist works as presenting positive, productive constraints upon the process of creation, and in doing so to replace the image of a determinate idea, fixed in the mind, with that of a plastic pattern, embroiled in the interactions between the brain and its environment.

Despite these qualifications, I think that both models face intractable difficulties.

The crucial problem with the aesthetic model is that it ultimately fails to distinguish art from craft, differentiating it from decoration, entertainment, and propaganda only by means of the types sensation and emotion it aims to induce, but for which it has no principled criterion. As articulated by figures such as Joseph Kosuth and Arthur Danto, it fails precisely insofar as it is unable to incorporate those cases of nakedly conceptual art that effectively enacted art’s secession from craft, such as Duchamp’s ‘Fountain’ and Warhol’s Brillo boxes. Whatever minimal aesthetic character these possessed was entirely insufficient to distinguish them as works of art, and their acceptance as art thus demands that we recognise a dimension of art orthogonal to sensation and feeling. Of course, for Kosuth and Danto this dimension is meaning, and they take it to define art, thereby subordinating aesthetics to semantics.

The corresponding problem with this semantic model is that it ultimately fails to distinguish art from other forms of communication, not just from poetry and literature, but equally from journalism and philosophy. Art refuses any constraints on expression, either on the topics it can address, or the types of message it can convey, and this makes it impossible to distinguish art from other forms of communication on the basis of content. Moreover, the very same gestures that free it from craft eventually dissolve the barriers between mediums that might have distinguished it on the basis of form. As explained by figures such as Susan Sontag and Gilles Deleuze, what comes to define art in the absence of aesthetic forms is not so much the contents communicated by the work but the practices of interpretation through which they are retrieved, practices which, for all their theoretical armaments, are essentially distinguished by the particular historical community to which they belong. Nevertheless, their proposed alternatives – erotics against hermeneutics, and composition against communication – return us directly to the aesthetic model already considered.

The only way to dissolve this dialectical impasse, and to work our way towards a properly synthetic position, is to explore the common assumptions about the mind of the beholder upon which both models are built. The most important of these is the received distinction between sensibility and intellect, which continues to organise the dialectic of aesthetics and semantics long after it has been complicated by philosophy and psychology.

There are three main oppositions that constitute this distinction: sensibility is understood as passive, as supplying the intuitive matter of thought, and as responsible for non-cognitive effects such as feelings, whereas the intellect is understood as active, as supplying the conceptual form of thought, and as responsible for cognitive products such as beliefs. The underlying idea organising these oppositions is that cognition is essentially discursive, meaning that conceptual understanding is essentially modelled on linguistic competence. This is not an entirely terrible idea. The significance of language is that it provides us with a general capacity to represent the features of our environment that outstrips the specific capacities to simulate certain features of our environment made available by our senses. Language is extensible – it allows us to think and talk about electrons, capitalism, and justice – while our sensory capacities are limited to the range of environmental stimuli they evolved for.

The problem with the discursive account of cognition is that it gives language a monopoly, covering over the crucial cognitive activities occurring beneath the linguistic level. The philosophical tradition mitigated this to some extent by appealing to the imagination – understood as a more active faculty of simulation that mediates between sensibility and intellect – but this remains little more than a place holder for the specific cognitive capacities upon which our more general, discursive understanding depends. It is here that the study of the brain comes to the fore, revealing as it does the various neural mechanisms involved in processing and integrating our sensations into a map of our environment, and the specific competencies that they enable, from motion tracking to facial recognition.

However, the crucial innovation in all this is the description of the brain as an information processing system, to which these various mechanisms belong as subsystems, processing certain sorts of sensory input and contributing towards certain sorts of behavioural output. This is significant because the language of information bridges the gap between sensibility and intellect, and thereby provides a common framework in which to address aesthetic and semantic issues. In essence, we can reframe the opposition between the form and content of art as a distinction between two types of content: the information processed by various specialised cognitive subsystems, and the information processed at the more general discursive level. This lets us treat meaning as information, even though not all information is meaningful.

Already, this suggests a rough picture of the circuit between artist and beholder as a flow of information, but as yet it tells us nothing about what distinguishes this from any other flow, be it the emotional information transmitted by a facial expression, or the semantic information communicated by text message. If we are going to provide a genuine alternative to the aesthetic and semantic models, we can’t distinguish the information flow the art work instigates by limiting it to one type of information, which means that we must locate an effect that genuine art has upon the beholder that isn’t restricted to any cognitive subsystem.

Having examined the dialectic between aesthetics and semantics, it’s clear that neither side of the debate entirely captures the important lessons of art’s history. The truth in the aesthetic model lies in its fidelity to stimulation, and the truth in the semantic model lies in its fidelity to cognition. The error of the aesthetic model is its focus on the non-cognitive dimension of stimulation, and the error of the semantic model is its focus on the communicative dimension of cognition. The simple truth about the purpose of art that has been revealed by the history of art’s struggle to define itself is the minimal condition of contemporary art: that it make us think. Put simply, the purpose of art is cognitive stimulation. To explain this properly requires a further distinction between cognitive process and cognitive product, or between the information processing subsystem that a given work activates and its results. In those examples favoured by the aesthetic model, the art work aims to stimulate our non-discursive information processing capacities, elevating their exercise by testing their limits, disrupting them, or simply pushing them beyond their everyday use. Colour discrimination, visual pattern recognition, emotional intelligence, etc., are all subject to stimulation in their own ways, the point being not to produce any particular understanding of their object, but to exercise them for their own sake. In those examples favoured by the semantic model, the art work aims to stimulate our discursive information processing capacities, inviting us to explore conceptual connections, resolve theoretical tensions, or indeed juxtapose interpretations, without demanding that we arrive at any particular conclusion. It’s entirely possible for art to stimulate our communicative capacities for purposes other than communication, so that its success doesn’t depend on whether we interpret it in the right way, but on whether the call to interpretation inspires us.

If there is anything that characterises the information flow proper to art, it’s the transmission of inspiration between artist and audience: the artwork does not embody a thought, but an invitation to think along certain lines. What remains to be understood is this: How does this invitation operate? Does it establish a shared cognitive workspace? Is this a matter of social imagination?