Botticelli’s painting is always referred to as idealized and timeless, and related to the Neoplatonic ideals that were common in the 15th century CE. Why is this? Where do these sensations come from, and why are they different from the ones we get from other painters? The answer has to do, at least in part, with the retina and with the brain. Retinal neurons extract edges from light contrasts. They provide the brain with a simultaneous and multiple analysis of the visual image, and one of them is a sharp edge description of the real world. In other words, the retina, besides providing information about color and movement, provides a sort of outlined and edged description of what we see, an abstract line-drawn version of everything around us. Leonardo said that “there are no lines in nature”; however, there are lines outlining objects, and they are in the retina!

Venus and Mars, c 1485. Tempera and oil on panel, National Gallery of London

What happens is that these outlined representations of objects are the optimal stimulus for the brain circuits that operate as pattern detectors. Brain pattern detectors are sets of interconnected neurons that receive the retinal information and resonate with specific patterns and forms, faces, cars, or cats, allowing us to categorize the world. Looking at Venus and Mars from this angle, Botticelli is offering us an optimal stimulus for our neuronal detectors of faces, hands, trees, flowers, helmets, etc. (one other time I’ll discuss how we can «see» little satyrs when there are no such things). This is why we perceive this image as «idealized,» because the painter is offering a processed version of the real world that mimics retinal processing and thus offers an optimal version for its resolution. We find them ideal because they fit our visual pattern detectors very well. Botticelli provides us with an image that is far from the real world as we see it (in reality, we do not know what the real world is like), but that is very close to the way the retina processes information. And it is also optimal for the categorization of the objects that surround us. And this is what fits Neoplatonism a philosophical current that was popular in the Italian Quattrocento. It emerged at the end of the third century B.C.,with Plotinus (204-270 A.D.), and had its roots in the philosophy of Plato and other philosophers of the antiquity. Beyond to their general systematic conceptions and metaphysics, or rather because of them, they regarded the world as imperfect copies of the Platonic world of forms or ideas. To them, the latter were immaterial and eternal, inhabitants of the spiritual world. And this is what painters like Botticelli intended to represent, and not so much the real world, as we see it, as later Florentine and Venetian painters would like to do.

Now the reader may ask: where do these visual pattern detectors come from? Are we wired to identify (categorize) every single object we are exposed to? Well, the answer is yes, we have this visual lexicon in our brains, and yes, we are wired to detect patterns. Now, does this mean that we are born with those patterns in our brains? The answer is no. What we are born with are the rules that allow us to build specific visual pattern detectors in specific regions of the brain. Throughout our lives, and particularly during our early years after birth, the statistical sampling of the world to which we are exposed drives the connectivity of visual neurons, so they fix the necessary connections to fire when we are exposed to faces, windows, cats, etc. In doing so, we no longer need to think about every object we see every time; the brain does the work for us. We build up this extraordinary ability to abstract general properties from particulars. We build up circuits that have encoded the universal “cat,” so we do not need to spare a second every time we see a Bengal, Siamese, or Persian cat, not to mention a dog. We see a cat. Note that this is like inverting the Platonic concept of Ideas and Forms. Ideal forms do exist, but instead of being in the realm of the immaterial spirit, they are embedded in specific neuronal circuits within our heads. As Semir Zeki says, the Platonic Ideal of a face is what is common to all faces; it is in fact the brain’s stored record” (Zeki, 1997).

In summary, Botticelli explored the brain and discovered the connections between technical tools and the evoked . He discovered that mimicking one specific aspect of retinal processing allows us to induce specific types of perceptions and reactions. Of course, I am not saying that this is the only technical resource that explains all the sensations or emotions that his beautiful paintings evoke. Not at all. What I want to stress is that well-known technical resources target specific rules and mechanisms of vision, which, in turn, drive perception in one direction or another. This makes a signature of their artistic gesture, the style. If we see the world according to certain rules, the painter needs to have an implicit knowledge of them. And this is why, in fact, they behave like intuitive neuroscientists.

Note: There is an extra trick to convey an unreal world to the viewer. The highest capacity for edge discrimination in the retina is concentrated in the fovea, where most cones are packed tightly. This is the region with highest resolution and the resources for color vision. In Boticelli’s paintings, the whole image is drawn at high resolution, it is fovealized, far away from our natural experience of the world. Note that if you fix your view on this reading, most of the surrounding scene is completely blurred (try the opposite, to read this lines fixing at the end of the paragraph.