Aristotle’s Ten Categories of Being
What Can We Say About Any Given Thing?
When we want to describe a thing (such as a room in a house, or a particular table, a fountain, a tree, or a person, etc.) Aristotle’s Ten Categories of Being tell us exactly what we can say about it. The 10 categories provide an outline of all the different ways we may speak about any given thing. The categories themselves are: Substance, Quantity, Quality, Relation, Action, Passion, Time, Place, Posture, and Possession.
What is the substance of the thing? In other words, what is essential to the very nature of the thing being described? Any attribute which could be separated from the thing (like its color or size) without destroying the concept of the thing itself is not part of its substance (or essence). When describing a dog, the color of the dog is not part of its substance because there are many different colors of dogs and their color doesn’t determine whether or not they are a dog. We would say that the particular color of this particular dog is merely an “accident” since it could be otherwise and he would still be a dog. If, however, I were to try to take away the fact that the dog is a mammal, or a living being, then I would be taking away some of its essential qualities which make up its substance or essential nature. So when describing a thing I can talk about its substance.
What is the quantity of the thing? I can describe how much or how many there are of a particular thing. I can discuss the single pile of dirty clothing in the corner of the bedroom with no less than fifteen discarded shirts.
What quality or qualities does the thing or place have? There are seven different kinds of qualities something may be said to have.
Habit: A deeply ingrained quality which is not easily changed.
“The man is apathetic about his fellow man.”
“The man loves his wife.”
Disposition: A quality that is easily modified, fleeting, or fickle.
“The man is hungry.”
“The horse is tired.”
Ability: A quality about what something can do.
“The man is thinking about the news report.”
“The dog sensed an unwelcome presence.”
Inability: A quality about what something cannot do.
“The stone was unfeeling as the rain struck it.”
“The idol had eyes but could not see.”
Sensible (perceptible): a quality of passively perceived by one of the five senses.
“The man felt his wife’s hand in his.” (touch)
“The waves of the sea were rolling toward the dock.” (sight)
“The dog is loud” (hearing)
The drink was very sweet. (taste)
The crypt was very malodorous. (smell)
Figure: a qualitative evaluation of the quantity of a thing.
“The dog was very large.”
“The road was particularly wide.”
Form: The aesthetic quality of a thing.
“The woman was beautiful.”
“The wolf had shaggy hair.”
“The hill was steep and covered in sharp rock.
What relation(s) does the place or thing have to other places or things? There are many kinds of relations, more than will be named here, but consider the following examples:
Familial: “John is Michael’s father.”
Spatial: “The sun was now directly above their heads.”
Proximity: “The college campus was 30 miles from his house.”
Dimension: “The church building in his town was much smaller than the one here.”
Time: “My wedding took place ten years before my brother’s wedding.”
Note: Relationships can be symmetrical (mutual) such as “A is 20 feet from B” is equal to “B is 20 feet from A.” Relationships can also be asymmetrical (non-mutual) such as “John is Michael's father” is not the same as saying “Michael is John’s father.”
What action(s) is the thing performing? In what way is the thing being described using its powers or abilities to affect other things or people around it? For instance one could say “the baseball bat struck the ball” or “the dog bit the boy.”
What passion(s) is the place or thing undergoing? Passion, in this sense, refers to the receiving of some action. Passion addressing what other things are doing to the thing you are concerned with. For example one could say, “Sam wept with pain when Mary slapped him” or “Christ was pierced for our transgressions” or “the stone was being worn away by long years of water dripping upon it.”
When or what time did a particular thing happen or when did it, does it, or will it exist as such. The statements, “The car ran out of gas this morning” and “Christ rose from the dead more than 2,000 years ago” and “I will be hungry this evening” are all related to time.
Where or in what place is a thing? The statements “Alfred the Great reigned in England” and “The homework study group is at my house this week” are both examples of place or physical location.
What is the posture of a thing? In other words, it is a question regarding the physical arrangement of the parts of a thing. For instance the statements “the man is sitting” or “the man is standing” are both about his posture or the arrangement of his body parts. Likewise, one could say “the tree branches are sagging” or “the dog’s ears are upright at attention,” and these would also be statements of posture.
What does the thing have in its possession which is not part of its own nature? Good examples of this are “The woman was wearing a bright colored shirt” and “the police officer was holding his pistol trained on the suspect.” Typically the category of possession is thought only to apply to beings with agency, meaning that inanimate objects and animals cannot properly possess anything.
So, there you have it. Now you can describe anything you want to and you can even state the particular categories which you are using in your description. By knowing the ten categories well you can also avoid certain errors and confusions in dialogue. Sometimes another person is speaking about a thing with one category in mind but another person is speaking about that same thing with a different category in mind. This kind of equivocation between two people that are speaking about the same thing might lead to accusations of contradiction or to the suggestion that the other person is a “perfect moron.” Being able to clearly delineate the categories is incredibly helpful for the sake of clarity.
Kant placed all these categories in the mind, which, unfortunately, was a mental error.
Great summary, thank you!