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On Light
- GenresPhilosophyScience
17 pages, Paperback
First published July 1, 1983
54 people want to read
About the author
Robert Grosseteste
49 books8 followersRobert Grosseteste (/ˈɡroʊstɛst/ GROHS-test; Latin: Robertus Grosseteste; c. 1175 – 9 October 1253) was an English statesman, scholastic philosopher, theologian, scientist and Bishop of Lincoln. He was born of humble parents at Stradbroke in Suffolk. Upon his death, he was almost universally revered as a saint in England, but attempts to procure a formal canonization failed. A. C. Crombie calls him "the real founder of the tradition of scientific thought in medieval Oxford, and in some ways, of the modern English intellectual tradition".
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Displaying 1 - 3 of 3 reviews
February 24, 2020
An interesting attempt, written by an important Medieval theologian, philosopher, and natural scientist (of sorts) to argue that Light is the first corporeal form. This little booklet introduces us to one approach to medieval cosmology, and an innovative appropriation and platonic modification of Aristotelian metaphysics. A quick read that is important for medieval scholars, but will be next to useless for those who are not interested in medieval natural philosophy and metaphysics.
December 27, 2012
The most poetic of 13th century scholastics. Again, I'm not sure how thoroughly I really, uh, grasp his conception of optics, it sure is lovely, veering often into what sounds to my shitty ears like apophatic mysticism and sometimes into electrifying technical finickiness.
January 2, 2026
I discovered Robert Grosseteste (1175 - 1253) just recently in the supplementary prayer book of the Anglican Church in Aotearoa, New Zealand and Polynesia, 'For All the Saints'. He is commemorated on October 9 in the Anglican tradition. He taught at Oxford, was master of the Oxford Franciscans, and became bishop of Lincoln.
He fought corruption in the church, and was known for writings in philosophy, mathematics, science and theology.
As a reader in theology in the newly formed Franciscan house of studies at Oxford, "he exerted a tremendous influence on the subsequent development of Franciscan thought... the noted Franciscan scholar É. Longpré credits him with having inspired 'almost all the principal doctrinal initiatives of Franciscan thought from Bonaventure to Duns Scotus inclusively.'" He was also a translator of Aristotle, Pseudo-Dionysius and John of Damascus, and took some of his ideas from Arab thinkers as well as Latin and Greek ones.
Here we have a 1942 translation from Latin by Clare Riedl of his short (seven-page) treatise 'De Luce', or in contemporary English, 'On Light (Or The Beginning of Forms)', which, fascinated, I decided to read, because, why not?
In it, Grosseteste treats light as metaphysical substance. Though he doesn't mention this explicitly, it is originary in that God created light in the first instance, and in fact created it before the sun and the moon. Grosseteste talks about light in two forms: lux and lumin (a differentiation apparently also found in St Basil and St Augustine). As Riedl tells us in her very useful and enjoyable introduction: "lux is light in its source, whereas lumen is reflected or radiated light".
She explains that the work falls into two parts. "The first part is concerned with 'light metaphysics' proper, that is to say, with the composition of material substance out of first matter and the first corporeal form of light. The second part contains a cosmogony based on this 'light metaphysics,' an account of the way in which light brought about the formation of the thirteen spheres of the material universe." So there you have it.
The thirteen spheres (where the firmament is the outer sphere), geo-centric cosmology was typical of the medieval era. Another quote from Riedl's intro:
"The second part of the treatise might well be called a 'philosophy of Genesis.' It gives the story of creation in terms of light. This light, in its capacity as first corporeal form united inseparably with matter, proceeded 'in the beginning' to extend matter along with itself into the form of a sphere. The outermost parts of the sphere were naturally more extended and rarefied than the inner parts. In fact their potency for extension was completely actualized. Thus in the outermost part of this sphere the firmament came into being. The firmament in turn diffused its light (lumen) from every part of itself to the center of the universe. This light gathered together the dense mass of matter inside of the firmament. In this process again the outermost parts of the mass came to be rarefied and extended to their full capacity and resulted in the formation of the second sphere. In this same way the light reflected from the second sphere produced the third sphere, and so on, until the nine heavenly spheres were brought into being, and also the four spheres of the elements: fire, air, water, and earth.
"Light furnishes therefore the principle of continuity in nature, for as the first corporeal form it is common to all things in the universe from the lowest of the elements, earth, up to and including even the firmament. Thus 'all things are one by the perfection of one light.' It is also the principle of distinction and multiplicity since the 'things which are many are many through the multiplication of light itself in different degrees."
"In Grosseteste's philosophy light is a very fruitful principle. The concept is not restricted to metaphysics as in the treatise On Light. In other works the principle is extended to different fields, such as psychology where light is brought in to account for the union of soul and body, or knowledge, where light serves as the means whereby the soul gets knowledge from sense data." In his wider work he also apparently applies the principle to mystical speculation.
Love it. Now, of course this isn't contemporary science - other than a vague similarity around the particle nature of light, a creative force expanding outwards, and such. But I love this picture conceptually - it's really quite beautiful and poetic. As mythos or poesis, if not hard science, it's easy to see the attractiveness of such ideas, coming as it does from a tradition that values beauty and/or elegance as an important feature of well-wrought scientific theory and philosophical speculation. I also love the interweaving of philosophy, theology and science (which are much more separate in our contemporary thinking than they once were), aiming for coherence of truth at multiple levels, and unifying principles.
Meanwhile, long live the little journeys of discovery that arise out of reading and the texts they bring across our paths.
He fought corruption in the church, and was known for writings in philosophy, mathematics, science and theology.
As a reader in theology in the newly formed Franciscan house of studies at Oxford, "he exerted a tremendous influence on the subsequent development of Franciscan thought... the noted Franciscan scholar É. Longpré credits him with having inspired 'almost all the principal doctrinal initiatives of Franciscan thought from Bonaventure to Duns Scotus inclusively.'" He was also a translator of Aristotle, Pseudo-Dionysius and John of Damascus, and took some of his ideas from Arab thinkers as well as Latin and Greek ones.
Here we have a 1942 translation from Latin by Clare Riedl of his short (seven-page) treatise 'De Luce', or in contemporary English, 'On Light (Or The Beginning of Forms)', which, fascinated, I decided to read, because, why not?
In it, Grosseteste treats light as metaphysical substance. Though he doesn't mention this explicitly, it is originary in that God created light in the first instance, and in fact created it before the sun and the moon. Grosseteste talks about light in two forms: lux and lumin (a differentiation apparently also found in St Basil and St Augustine). As Riedl tells us in her very useful and enjoyable introduction: "lux is light in its source, whereas lumen is reflected or radiated light".
She explains that the work falls into two parts. "The first part is concerned with 'light metaphysics' proper, that is to say, with the composition of material substance out of first matter and the first corporeal form of light. The second part contains a cosmogony based on this 'light metaphysics,' an account of the way in which light brought about the formation of the thirteen spheres of the material universe." So there you have it.
The thirteen spheres (where the firmament is the outer sphere), geo-centric cosmology was typical of the medieval era. Another quote from Riedl's intro:
"The second part of the treatise might well be called a 'philosophy of Genesis.' It gives the story of creation in terms of light. This light, in its capacity as first corporeal form united inseparably with matter, proceeded 'in the beginning' to extend matter along with itself into the form of a sphere. The outermost parts of the sphere were naturally more extended and rarefied than the inner parts. In fact their potency for extension was completely actualized. Thus in the outermost part of this sphere the firmament came into being. The firmament in turn diffused its light (lumen) from every part of itself to the center of the universe. This light gathered together the dense mass of matter inside of the firmament. In this process again the outermost parts of the mass came to be rarefied and extended to their full capacity and resulted in the formation of the second sphere. In this same way the light reflected from the second sphere produced the third sphere, and so on, until the nine heavenly spheres were brought into being, and also the four spheres of the elements: fire, air, water, and earth.
"Light furnishes therefore the principle of continuity in nature, for as the first corporeal form it is common to all things in the universe from the lowest of the elements, earth, up to and including even the firmament. Thus 'all things are one by the perfection of one light.' It is also the principle of distinction and multiplicity since the 'things which are many are many through the multiplication of light itself in different degrees."
"In Grosseteste's philosophy light is a very fruitful principle. The concept is not restricted to metaphysics as in the treatise On Light. In other works the principle is extended to different fields, such as psychology where light is brought in to account for the union of soul and body, or knowledge, where light serves as the means whereby the soul gets knowledge from sense data." In his wider work he also apparently applies the principle to mystical speculation.
Love it. Now, of course this isn't contemporary science - other than a vague similarity around the particle nature of light, a creative force expanding outwards, and such. But I love this picture conceptually - it's really quite beautiful and poetic. As mythos or poesis, if not hard science, it's easy to see the attractiveness of such ideas, coming as it does from a tradition that values beauty and/or elegance as an important feature of well-wrought scientific theory and philosophical speculation. I also love the interweaving of philosophy, theology and science (which are much more separate in our contemporary thinking than they once were), aiming for coherence of truth at multiple levels, and unifying principles.
Meanwhile, long live the little journeys of discovery that arise out of reading and the texts they bring across our paths.
Displaying 1 - 3 of 3 reviews