How do we form abstract concepts—like “dog”—given that we only experience concrete, particular objects—like “Fido”?
Therese Scarpelli Cory, a Notre Dame assistant professor of philosophy, examined Aquinas’ answer to this question in her article, “Rethinking Abstractionism: Aquinas’ Intellectual Light and Some Arabic Sources.”
Her work, published in the Journal of the History of Philosophy, was awarded the publication’s 2015 best article prize in January.
Cory argues that Aquinas uses what she terms the “active principle model” to explain the formation of abstract concepts. The concept of “dog” results from a chain of actions beginning with the object, Fido, and ending in a person’s mind. With the help of an “intellectual light,” the neurological impressions in an observer’s senses and imagination cause immaterial, abstract impressions such as “dog-ness” or “justice” in her immaterial intellect.
“I became curious about Aquinas’ frequent references to an ‘intellectual light’ that helps us form abstract concepts,” she said. “Scholars have assumed this language of light is metaphorical. But the language seemed to be so important to Aquinas that I began to wonder if there was some technical sense that was being overlooked.”
Cory delved into theories of physical light that were circulating in European scientific circles at the time of Aquinas—the most important of which were the theories of Arabic philosophers Avicenna and Averroes.
She discovered that Aquinas, drawing on these sources, was explicitly modeling the behavior of this mysterious intellectual light on the behavior of physical light.
“He thought that physical light enables us to see by helping colored objects to cause an image in the eye,” Cory said. “In an exactly analogous way, the intellectual light enables us to understand what a dog is by helping our sensory impressions of Fido to cause an abstract image in the intellect.”
Cory said she hoped the award would draw attention to the new philosophical ideas that can be unearthed by reading classic figures such as Aquinas with attention to historical context.
“When we go back to the context in which he was working and read him in connection with the Greek and Arabic sources that influenced him, it’s possible to open up a fresh perspective on his thought,” she said. “And this new perspective, in turn, can suggest new and interesting approaches to questions that are still current in philosophy today.”