One of the unifying themes across Grosseteste’s ‘scientific’ treatises is that he carefully observed the natural world around him and furthermore assumed that there should be a set of fundamental, universally applicable principles explaining the ordered complexity with which he was confronted. For Grosseteste creation was an act of divine generosity, an overflowing of God’s joy and goodness, and, as a product of the fount and origin of reason (as well as love, justice, joy and so forth), was itself inherently rational. Nature forms a source of knowledge about God alongside the revelation of Scripture.
In pursuing his goal of uncovering the hidden governing principles of nature, Grosseteste employed rather sophisticated modelling methodology. The mathematical and geometrical richness of his thought tends to be initially hidden to modern-day readership through their being laid out verbally. However, during the collaborative reading sessions joint effort between medievalists and scientists has repeatedly allowed the group to ‘translate’ Grosseteste’s models into visual and mathematical representations that are more widely accessible. Far from superimposing modern-day understanding onto the text, this translation-technique unlocks to contemporary audiences the mind-blowing complexity and coherence in these 13th-century explanatory accounts.
The key role of mathematical modelling implicit in the text goes together with the recurrence of counting arguments. In the De colore we encountered seven colours descending from whiteness and seven ascending from blackness, and in the De luce we met nine perfected celestial and another incomplete and corrupted sphere below the firmament. In the De generatione sonorum the Ordered Universe group is now grappling with seven motions (of which Grosseteste deems two to be irrelevant) that he takes to produce the five vowels.
Setting aside the shared methodology of mathematical modelling (expressed verbally) and counting arguments, there are themes that seem to reappear across the treatises looked at so far. For instance, Grosseteste’s accounts of the nature of both colour and sound (in the De colore and the De generatione sonorum) crucially build on body interacting with either light or motion. He starts the De colore by stating that ‘Colour is light embodied in a diaphanous medium.’ In the De generatione sonorum, after explaining the nature of tremor induced when an object capable of making sound is struck, the body is set in motion. In other words, in the Grossetestian accounts of colour and sound, these two physical phenomena arise when body is either subject to light being embodied in it or when body is set into motion.
The treatises on colour and on sound share the further commonality that they are both concerned with what philosophers would call secondary qualities. Roughly speaking, the nature of secondary qualities like colour and sound is at least partly determined by the nature of our perceptual systems in a way that the nature of primary qualities, such as shape, is not. As Clive Siviour pointed out during one of the collaborative reading sessions, it has been argued that sound only ‘exists’ when there’s someone there to perceive it. Such claims build on the fact that physical-level descriptions reduce sound to motion and colour to different wavelength compositions of light. To be able to explain the distinct phenomenologies of colour and sound, reference must be made to the nature of human perceptual systems. During the past three years I had the pleasure to write several essays on variations of this theme, and despite many sleepless nights spent reading numerous people’s thoughts on this topic I’m still not sure whether or not to agree with Clive Siviour’s non-existence claim regarding secondary qualities like sound. But be this as it may, what matters with regards to Grosseteste is that he wants to explain colour and sound as physical rather than as perceptual phenomena. Nonetheless, as Hannah Smithson put it, perceptual mechanisms might be seen in some way as his ‘measurement device’ with which he observes the physical phenomena he’s interested in – and this results in his ‘measurements’ being confounded by the very nature of these perceptual mechanisms.
All in all, irrespective of the correctness of Grosseteste’s models (as measured against currently available evidence), his way of looking for fundamental and unifying principles explicating the orderliness of the physical universe is a case in point for modern-day scientists. Grosseteste’s methodology was highly abstract and mathematical, and one may be able to argue that in many ways it parallels modelling approaches in modern science. However, despite some references to ‘experimentum’ the consensus seems to be that he did not engage in experimental investigations in the modern sense of the word. Rather, he started his modelling work from having carefully observed the physical properties of the world around him. In an age in which experimental manipulations seem to be the gold standard for advancing scientific knowledge, it may be worth directing attention back to fruitful outcomes that can be generated through careful observation, a take-home message summarised by Hannah Smithson during the public lecture under the slogan ‘observation is key’. Furthermore, the complexity and richness of Grosseteste’s accounts serves to prove that far from being dark, the Middle Ages were the time of bright thinkers who did not differ all that much from modern-day scientists in what spurred their efforts, namely the desire to understand more about the governing principles of the world in which we live, however differently they might derive its principal principle.
Ulrike (and Giles)