This article features the work of University of Texas at Austin Philosophy Professor Mark Sainsbury. The image is by artist Yelena Bryksenkova and reproduced here courtesy of Oxford University Press.

It’s 25 minutes until your shift ends, but you have finished all the work you needed to do for the day. You click through your personal emails, browse twitter, and allow your mind to wander. What are you going to make for dinner tonight? Salmon sounds good. It would go well with the bottle of pinot grigio hanging out in your refrigerator. Or maybe you will luck out, and swordfish will be on sale. Swordfish are such funny looking creatures with their protruding noses—kind of like narwhals, the unicorns of the sea.

Why is is that you are suddenly thinking about unicorns, when just a minute ago you were planning your dinner? And why is a unicorn—a creature that does not exist in physical reality—the first thing you picture when you think about a real animal? And how could you pass so effortlessly from thinking about a real animal to thinking about a nonexistent one?

According to University of Texas Professor of Philosophy Mark Sainsbury, conjuring a swordfish steak, a narwhal, and a unicorn in our mind are not such different processes. His new book Thinking About Things (Oxford University Press, 2018) presents the theory that “thinking about, wanting, hoping and similar states are intentional states: they are directed on things or are about things.” When we think about things, our minds deploy representations of those things. Sainsbury’s book explains how these representations are formed and what they refer to in a broad spectrum of relationships to other things and ideas.

Representations are key to the way that our minds direct thoughts and desires, but the representations we conjure in thought are not the object of such thoughts and desires. Sainsbury proposes that “representations are what we think with, and normally not what we think about, just as our eyes are what we see with, and normally not what we see.” Words and images are express concepts, and when you put these concepts together, they create meaning.

When I say that I am thinking about unicorns because they look like narwhals, I am not using the concept of unicorns in the usual way—that unicorns are frolicking around my apartment building. Instead, the concept of unicorns is being used in my thoughts. I am using the words and concepts correctly even though there aren’t any physical unicorns to talk about because concepts don’t have to refer to anything in order to be used in thinking. There may not be any unicorns, but there are plenty of thoughts about them.

Purchase Thinking About Things from Oxford University Press

Learn more about Mark Sainsbury’s other works

See other work by artist Yelena Bryksenkova