Theories of Vision and Light: Magic and Science
Tuesday, August 10th, 2010First of all, it’s been a while since I had the time to post here. Ever since I started the full-time PhD, research has naturally taken precedence to my other interests. But, the Esoteric Coffeehouse blog has never been fully out of the picture and I’ve been thinking of ways to resuscitate it. Given my reduced amount of time available, I have decided that I will have to sacrifice some of the quantity of information that I can provide in this blog. Instead, the ‘new’ version of the Esoteric Coffeehouse will run shorter posts, perhaps with some pointers where to read further on some information. I also tend to make it more informal by providing more of my own thoughts and experiences on studying esotericism. Well, we’ll see how it goes.
I’ve been looking at light and vision theories for the past week. As it turns out, up to the modern period there existed two main competing models: the ‘intromission’ and ‘extramission’ theory. The intromission is similar to the way we understand vision today: as light ‘entering’ our eyes and projecting the shape of perceived things within. This theory was supported mainly by Aristotelian and atomistic philosophers and was made an official part of science by Johannes Kepler. The extramission theory, on the other hand, was favoured by Pythagoras, Plato, Euclid, Galen and the Neoplatonists. According to it, the eyes ‘emit’ light, throwing ‘arrows’ that reflect one’s emotional state. Interestingly, this theory fits very well with the popular beliefs in the evil eye or love at first sight. In both cases, the onlooker projects his/her feelings of hate or love. The light emanation is imprinted within the soul of the person looked at.
Today, the triumph of science and its wholehearted adoption of the intromission theory has rendered the idea that eyes can project light obsolete. This is in fact ironic, since early mathematicians and physicists tended to support the extramission perspective, using Euclidean geometry to show how light projects outside the eye. However, interest in psychological phenomena has been challenging the official scientific perspective. The reality of the sense of being stared at from behind or through CCTV has been proven through empirical research by Rupert Sheldrake and others. Sheldrake is currently making the argument that the intromission theory should be revised. It would be interesting to think about the consequences of the idea that eyes may send forth rays of light and how that might affect our understanding of the ’superstitions’ of popular magic.
If you want to read more, Rupert Sheldrake’s articles are available on the web here and here. I also recommend David C. Lindberg’s scholarly studies, particularly Theories of Vision from al-Kindi to Kepler (1981), a preview of which can be found on Google Books.

