Question

...
Mark

Empty class

In the Existential Fallacy, I do not understand what is meant by an empty class. What is meant by an empty class ? Where is the empty class in the examples given ?

asked on Wednesday, Jan 04, 2023 07:35:07 AM by Mark

Top Categories Suggested by Community

Comments

Want to get notified of all questions as they are asked? Update your mail preferences and turn on "Instant Notification."

Uncomfortable Ideas: Facts don't care about feelings. Science isn't concerned about sensibilities. And reality couldn't care less about rage.

This is a book about uncomfortable ideas—the reasons we avoid them, the reasons we shouldn’t, and discussion of dozens of examples that might infuriate you, offend you, or at least make you uncomfortable.

Many of our ideas about the world are based more on feelings than facts, sensibilities than science, and rage than reality. We gravitate toward ideas that make us feel comfortable in areas such as religion, politics, philosophy, social justice, love and sex, humanity, and morality. We avoid ideas that make us feel uncomfortable. This avoidance is a largely unconscious process that affects our judgment and gets in the way of our ability to reach rational and reasonable conclusions. By understanding how our mind works in this area, we can start embracing uncomfortable ideas and be better informed, be more understanding of others, and make better decisions in all areas of life.

Get 20% off this book and all Bo's books*. Use the promotion code: websiteusers

* This is for the author's bookstore only. Applies to autographed hardcover, audiobook, and ebook.

Get the Book

Answers

...
Bo Bennett, PhD
3

Example #2:

All forest creatures live in the woods.

All leprechauns are forest creatures.

Therefore, some leprechauns live in the woods.

The class "leprechauns" is empty, because there are no such thing as leprechauns. In other words, there are no leprechauns. Yet the conclusion states that "some leprechauns live in the woods" which cannot possibly be true if it is true that no leprechauns exist (that is, "leprechauns" is an empty set).

answered on Wednesday, Jan 04, 2023 07:43:04 AM by Bo Bennett, PhD

Bo Bennett, PhD Suggested These Categories

Comments
...
3
TrappedPrior (RotE) writes:

For OP, I'd add that in logic, 'some' means 'at least one member of the set', whereas 'all' simply means 'every member of the set'. Thus, 'some' implies that set members actually exist - there's no such implication for 'all'.

So if I say 'some leprechauns live in the woods', I'm suggesting that leprechauns actually exist - but they don't. So the particular conclusion does not follow from the general premise.

posted on Wednesday, Jan 04, 2023 08:29:12 AM