CRITICAL THINKING - Fundamentals: Soundness [HD]

In this video, Aaron Ancell (Duke University) discusses the philosophical concept of soundness. After reviewing validity, he defines soundness: an argument is sound when it is valid and has all true premises. He reviews a few examples of sound and unsound arguments, and he encourages you to develop sound arguments on your own.

Help us caption & translate this video!

[justamoteofdust]

A) this video is informative.
B) I love videos that are informative.
C) therefore, I love this video.

[p.hhenry]

1) Humans need oxygen to survive
2) You are a human
Conclusion: Therefore, you need oxygen to survive.

[jameseast]

Such a convoluted way of explaining basic logic.

[Battusai]

I might be coming at this from a completely wrong angle but while the concept of a sound argument is easy to define, in practice it becomes undermined by "to the best of our knowledge" on purely factual matters, and "in my experience/opinion" on subjective matters.

[balynabad]

This helps me so much for my daughter. Thank you so much

[stinkleaf]

Now service humanity by applying this test on political arguments that are swarming the world scarce supply of rationality.

[camilogomez]

Thanks a lor, I'm loving this topic and this videos are very helpful and well explained

[OnoxOrion]

There is a slight technicality which I think makes the last argument invalid, although it may depend on the translation between logic and language. One would also need that "whales exist" as a third premise. If whales did not exist then vacuously they would all be mammals and have fur.

[darrenchen]

P1) I just watched this video.
P2) This video was informative.
C) I was informed by this video.

[enchypeachy]

P1) Trees produce oxygen
P2) Oak is a tree
C) Therefore, oak produces oxygen.

[invisible]

I laughed so hard at the unsound valid arguments lmao

[UzairAlvi-qsfd]

@1:05 did you meant to say "all cats are purple" or "all cats are people"

[Nikolai.A.McGuire]

P1: I'm alive
P2: I'm a human
P3: Humans need 02 to survive
Thus; I need 02 to survive.

[progressivehouseclusive]

Hi, I just want to make sure if whether or not my answers are incorrect. please help me with these as my instructor says arguments 1 and 2 are invalid which I answered VALID

argument 1 - "If Miriam went to medical school, then she is a doctor. Miriam is a doctor. Therefore, Miriam went to medical school."

argument 2 - "All mammals are animals. All birds are animals. Therefore, all birds are mammals"

While the argument 3 is valid according to my instructor which I answered invalid.

argument 3 - "Maria is Estela’s sister. Estela is Sophia’s mother. Therefore, Maria is Sophia’s aunt."

please can someone explain why my answers are wrong?

[jonchurey]

With the final argument being a sound one, and a valid conclusion has to follow from the premises, could one not argue that no mammals have fur?

[paradigmarson]

What about arguments that are valid in that the conclusions follow from the set of all premises and don't require *every* premise to be true, just some of them? Would that not count as an argument? Perhaps it wouldn't count as an inference but would count as an argument? I'm just being pedantic and pointing out exceptions. If this confuses you, ignore me.

[Choiwaru-otousama]

P1.)The sky is blue from the sun during the day.
P2.) The sky gets darker through the night.
C.) Therefore you cannot see the light from the sun at night.

[SP-qiur]

1:05 you said "people" instead of "purple"

[deltamico]

Shouldn't be the last argument invalid because there is nothing like "there is more species in the mammal group"?

[tahliajoi]

This helped me so much. My textbook made no sense lol