## [[Introduction This]] paper explores [[the relationship between]] [[aesthetic experience]] and [[psychedelic experience]]. Intuitions might pull either way here. On the one hand, people who have taken psychedelics will very often speak about their experiences in aesthetic terms. On the other one might place LSD, magic mushrooms, in the 'mindless hedonism' category: tripping is not, in and of itself, aesthetic, in the same way that getting drunk is not, in and of itself, aesthetic. A sceptic might try to make their complaints more acute by asking us to consider two connected questions. First, what are [[the objects]] of an aesthetic [[psychedelic experience]]? We typically think of the targets of [[aesthetic appreciation]] as shareable; (you and I can both appreciate the same painting or landscape, for example). But psychedelic experiences vary considerably across individuals and occurrences. Neither does it seem plausible to say that [[the objects]] of appreciation are the psychedelic artifacts themselves insofar as: the perceivable properties of a tab of acid (size, shape, taste) are not that much different to a postage stamp. This leads to the second question: how do we appreciate whatever it is we are appreciating? Traditional models of [[aesthetic appreciation]] often involve [[perceptual attention]] to external objects. However, given that experiences elicited by psychedelics are, to say the least, non-standard, it is not obvious whether a similar model is plausible for [[psychedelic aesthetics]]. Here we suggest that both questions can be answered by considering [[psychedelic aesthetics]] as a peculiar type of *pictorial* aesthetics. Both pictures and psychedelics have the function of creating distinctive sorts of perceptual, or perception-like, experiences. People look at pictures to have perceptual experiences of a particular type. People take psychedelics to have perceptual (as well as perhaps non-perceptual) experiences of a particular type. This functional similarity provides our starting point: if pictures and psychedelics both create these distinctive perceptual experiences, perhaps we appreciate them aesthetically in similar ways. ## Challenges to [[Psychedelic Aesthetics]] One might wonder whether a comparison with images and their aesthetics is really a promising route to take when thinking about psychedelic experiences. To evaluate [[this approach]], we need to understand that pictures can be appreciated aesthetically in two distinct ways. First, we can appreciate pictures for the scenes they enable us to perceive - the content they depict, whether landscapes, people, or objects. Second, as [[Bence Nanay]] has argued, we can appreciate pictures for the relationship between their physical elements (brushstrokes, colours, textures) and what these elements depict - what he calls "design-scene properties." For example, when looking at a Cézanne painting, we might appreciate how particular brushstrokes create the impression of pine needles, attending to both the physical marks and what they represent. If we attempt to extend this model to psychedelics, two challenges emerge: Can we have a scene-oriented aesthetics of psychedelics? Appreciating pictures for their scenes can itself take several forms. At the most basic level, pictures might simply show us beautiful real-world objects, with the beauty belonging to the object rather than the picture itself. Similarly, one might object that psychedelics merely enhance aesthetic experience like a lens or microscope - they simply allow us to see existing beauty more clearly or intensely. The beauty belongs to the objects perceived, not to the psychedelic experience itself. Can we have a design-oriented aesthetics of psychedelics? In pictorial art, we appreciate the relationship between physical marks on a surface (the design) and what those marks depict (the scene). But there seems to be no analogous design elements in psychedelic experiences. Unlike paintings, where we can attend to both the paint and what it depicts, there is no reason to think that there is an experiential analogue of this. The features of the physical world which realise our conscious experiences—neural processes—are not the sort of thing that we can perceive or attend to. In this paper, we will address both challenges, showing how psychedelics can be the objects of both scene-oriented and design-oriented aesthetic appreciation. To do this, we will draw on the predictive processing framework, which Letheby has applied to understand the nature of psychedelic experience. We extend this application to explain how psychedelics can be proper objects of aesthetic appreciation. ## Predictive Processing Framework On the predictive processing framework, perception is not a passive, bottom-up process of building representations from incoming sensory data. Instead, perception involves the brain actively generating predictions about what it expects to encounter, then comparing these predictions with actual sensory input. Any mismatch between prediction and input generates "prediction error", which the brain tries to minimise. This prediction error minimisation happens across multiple levels of a hierarchical system. Higher levels in the cortex generate abstract, categorical predictions (like recognising a 'tree'), while lower levels produce more specific predictions about expected sensory features (shapes, textures, colours). Higher-level predictions flow downwards through the hierarchy, while prediction errors—signals representing mismatches between predictions and sensory input—travel upwards, gradually updating the brain's models of the world. The brain has multiple ways to minimise prediction error. Most obviously, it can revise its predictions to better match sensory input. However, it can also adjust how much weight it gives to different predictions versus sensory signals through a mechanism called "precision-weighting". This process determines how much influence a given prediction error has on updating our models. High-precision prediction errors significantly impact our perceptual models, while low-precision errors are effectively ignored. This precision-weighting mechanism serves as the brain's way of handling uncertainty—giving more weight to reliable information and less to unreliable information. For our purposes, precision-weighting is particularly important because it helps explain how attention works in the brain. When we attend to something, we're effectively increasing the precision of prediction errors associated with that object or feature, allowing those signals to have greater influence on our perception. As we'll see, psychedelics appear to alter these precision-weighting mechanisms, which helps account for their distinctive effects on perception and experience. This framework provides exactly what we need to address our two challenges. For scene-oriented aesthetics, predictive processing helps explain how psychedelics create distinctive ways of seeing that go beyond merely enhancing pre-existing aesthetic properties. For design-oriented aesthetics, it offers a way to understand how psychedelic experiences can make perceptual processes themselves partly available for aesthetic appreciation. In the following sections, we'll develop both of these approaches in detail.