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Circular Definition

Description: A circular definition is defining a term by using the term in the definition.  Ironically, that definition is partly guilty by my use of the term “definition” in the definition.  Okay, I am using definition way too much. Damn!  I just did it again.

Logical Form:

Term 1 is defined by using term 1 in its definition.

Example #1:

 Circular definition: a definition that is circular.

Explanation: The definition is not at all helpful because we used the same words in the term to define them.

Example #2:

Flippityflu: smarter than a Floppityflip.

Floppityflip: dumber than a Flippityflu.

Explanation: Here we have two definitions that result in a slightly larger circle, but a circle nonetheless.

Exception: Many definitions are circular, but in the process of defining, there might be enough other information to help us understand the term.

Ethics: moral principles that govern a person's behavior or the conducting of an activity.

Moral Principles: the principles of right and wrong that are accepted by an individual or a social group.

Principles of Right and Wrong: moral principles or one's foundation for ethical behavior.

Tip: Don’t be too quick to call “fallacy” with this one. As demonstrated in the definition, some words in the term can be reused if they are commonly understood.

Nimbus cloud: A cloud that produces precipitation.


Lavery, J., & Hughes, W. (2008). Critical Thinking, fifth edition: An Introduction to the Basic Skills. Broadview Press.

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Eat Meat... Or Don't.

Roughly 95% of Americans don’t appear to have an ethical problem with animals being killed for food, yet all of us would have a serious problem with humans being killed for food. What does an animal lack that a human has that justifies killing the animal for food but not the human?

As you start to list properties that the animal lacks to justify eating them, you begin to realize that some humans also lack those properties, yet we don’t eat those humans. Is this logical proof that killing and eating animals for food is immoral? Don’t put away your steak knife just yet.

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