Gross sits at intersection of philosophy, science

Professor interested in how great advances of thinking about the mind raise philosophical questions

This article is part of the Provost's Project on Innovation series

Steven Gross expands the consciousness of consciousness. As an innovator in the philosophy of mind and language, he is always working toward broadening the definitions and clarifying the boundaries of scientific study. Scientists interested in the nature of consciousness, for example, will break new ground, while a philosopher brings new areas of consciousness study to the fore.

"There are actually various different things that can fall under that heading," Gross says. Sometimes consciousness refers to our having access to information used in reasoning and planning action. But sometimes the term refers to what we experience. There's a difference, he says, in being in the state of tasting an apple and planning to grab the next apple. But they are both termed consciousness.

Scientists want to be clear about conceptual matters like these, and philosophers can draw distinctions that may help sharpen their focus when they look for neural correlates of consciousness.

The marriage of philosophy and science is not new. "Physics used to be called natural philosophy until it became scientific," Gross says. Plato was deeply influenced by Euclidean geometry. Aristotle reflected on the nature of biology and physics, as they were understood in his day. And many of the most important figures of the scientific revolution were philosophers; for example, Leibniz was a co-inventor of the calculus, and Descartes first advanced conservation laws in physics. It's not a coincidence that they happened to be good at two things.

So Gross, associate professor of philosophy and cognitive science, has been interested in how the great advances in thinking about the mind/brain raise philosophical questions and how a philosopher could help interpret these things.

What draws his attention is the excitement of understanding our own ability to understand. For instance, a person who is good at riding a bike may not know how to explain bike riding, while a mechanical engineer can easily explain the kind of leaning and weight shifting that occurs. It is unclear, however, whether our learning about the principles of staying on a bike can actually help us become better bike riders.

"Similarly," he says, "we're all able to reason, and we [can] assess some arguments as being good or bad. ...But it's a whole other matter to have a good theoretical grasp of what accounts for good reasoning." Especially important is the kind of reasoning that can't be simulated by machines: nondeductive reasoning. Deductive reasoning is called monotonic. "If you have premises from which your conclusion follows, in deductive reasoning, no added bit of further information—no new thing that you learn, no further premise you add—will change the conclusion."

"Start with Euclid's axioms," Gross says, "and you can get that Euclidean triangles have 180 degrees." Adding further information won't change that.

But the same does not hold for nonmonotonic reasoning. Gross cites Sherlock Holmes as an example of clue gathering that requires nondeductive inference, or nonmonotonic reasoning, to get to an interesting conclusion. "If I tell you that Sally's sweater is in her office, there's one piece of information." Gross adds a new piece: Whenever her sweater has been on that chair in the past, Sally's been in the building. From that, we can infer that Sally has been in the building today. But here's a new piece of information: "Sally tripped and fell and hit her head and was carried off on a gurney to the hospital." That changes what conclusion we can reasonably draw. And new information—that she was perfectly fine and was back by lunchtime—changes the conclusion still again.

"That's the human predicament, the nature of scientific reasoning." New information can change everything, and that's not the kind of reasoning we can mechanize as things now stand. And where others in science might desire, as D. H. Lawrence said of an American desire, to "let a machine do the thing," innovation in this area, says Gross, "depends on smart people working hard, and we can't [at the moment] hand it off to the computer. Studying why that's the case is itself a fascinating thing. It's revealing about the nature of human beings."

Innovation requires getting "down and dirty." And that means a philosopher interested in these matters must have her hands in both philosophy and science. Gross believes that a philosopher cannot have something really useful to say unless she knows the science well.

For the past three years, down and dirty for Gross has included studying the relations between science and religion, for which he received a grant. One of his greatest challenges is that "soft matter, like the brain, doesn't fossilize," so when thinking about how cognitive competencies have evolved, scientists must be clever in finding indirect sources of evidence. "It's easier to come up with a hypothesis about why it might have been useful to have some cognitive capacity and much harder to show how it came to be—because you don't have this fossil record." It's further complicated because the passing down of human culture can have an impact on biological evolution.

Gross cites lactose intolerance as an example: Populations evolve to have it or not depending on societal proximity to domesticated cows. "It's hard enough having good models for biological evolution but then to bring in this cultural aspect too—it really complicates things."

With regard to religion, it has been found that some stories transmit more easily than other stories. Anthropologists and developmental psychologists have collaborated in trying to address these questions of cognition and culture. Of particular interest is why some religions thrive over others. "Some religions are easier to pass down than others through storytelling. They're more memorable. Maybe they just grab people's attention better."

Among the various claims Gross can make is that the attention of children is drawn by certain characters that are intuitive in some respects and unintuitive in others. They are characters from the natural world, but "they cross boundaries. Animals that talk, for example, or a creature that can be invisible and becomes visible again. It doesn't flummox them because they think, 'Oh, it's a talking rabbit. I know what rabbits are.'" That they talk makes the story memorable, and this could be the kind of thing that makes one religion easier to spread than another.

These hypotheses can be tested scientifically, across cultures. Will they hold up? Thanks to Gross' work, it's not only a question for philosophers and those who study the nature of religion in the humanities. It's also a question for scientists.