Validity does not equal to truth. However, if all premises are true then the conclusion must be true. This makes an argument valid. An invalid argument depends on the truth of the premises.
If you're struggling with the information clicking, I would recommend watching again. The biggest point of this is that the reasoning is the most important thing when trying to determine if something is valid. Wether it is true or false doesn't necessarily matter because we aren't looking at most arguments from a real world lense anyways.
The plans for a building cannot be "true" or "untrue." They can, however, be structurally sound (valid) or structurally unsound (invalid).
Now, I tell you I'm going to build a house in Wonderland. I show you the blueprint. It is mathematically and structurally perfect—i.e., valid. If Wonderland were real, it would work flawlessly. And that validity is totally irrelevant to the "truth" of my premises, being that Wonderland is a real place I can build a house in.
How I am understanding this is even though the premises can be false, as long as the premises match the conclusion, it is a valid argument. You aren’t looking if the actual claims are “true” or factually correct. You are looking at the form of the argument and if the premises support the conclusion. If it does, then it's a valid argument.
To tie it back to subsets/supersets: an argument is valid if the set of all universes where its premises are true is a subset of the set of all universes where its conclusion is true. So the premises' truth is sufficient for the conclusion's truth, and the conclusion's truth is necessary for the premises' truth.
What happens if we are asked to take a case on in the real world and there are false premises that support the validity of the argument you're trying to make. Should we lie to juries that we are giving them true premises when giving false ones while obscuring true premises that harm the validity of our argument? How do we decide if the ends justify the means? Doesn't that mean we have an interest in being dishonest to people? Surely most other people conflate truth with validity.
so basically, your job isn't to decide whether the statements are true or false. Instead, you're focused on analyzing the structure of the argument to determine if it's logically valid.
What I got from this is that technically with each scenario we are operating within a closed universe that functions from different 'truths' each time?
Whether a claim is false in the real world or not does not matter because the reasoning of the argument determines whether it's valid or invalid.
I suggest rewatching the video. Initially, when I first watched it, I questioned myself because, like some of you in these comments, I was told to leave my real-world knowledge outside. That still applies. You just have to assume a claim is correct if it's a valid argument.
Basically when dealing with truth we are dealing with how the premises and conclusions make sense and see whether or not the argument has holes ( aka what assumptions can you make).
When dealing with validity we are just making sure everything is consistent , if not then it becomes invalid.
If an argument is valid, it means the argument is logically correct (The premise supports the conclusion and does not contradict one another.) Even though the premises are false, it can still be a valid argument.
The sufficient condition's presence guarantees the outcome of the necessary condition. Is that the relationship? The necessary condition can not happen until the sufficient condition is established, correct?
Maybe I missed it in the video, but for me it is also important to understand that just like a valid argument can have false premises, an invalid argument can have true premises.
Important to be on the lookout for this. Just because the premises and conclusion of an argument are all true does not guarantee the validity of the argument. If I told you that:
A. cats are mammals
and
B. siamese is breed of cat
then
C. Burmese cats are mammals
All these things are true, but the logic of the argument is flawed and therefore invalid.
If I am taking the LSAT after August 2024 is it necessary that I watch all these videos on formal and informal logic? Since we won't be doing the logic games?
Is it even worth reading all of these passages before continuing onto exercises and practice tests again after the diagnostic? I feel like I am reading a bunch but am not able to apply any of it right after learning about it.
It is really freeing to not assess whether or not something is true and instead consider if something is valid or not. It allows you to just assume the test is giving you enough baseline for knowledge and reject assumptions that could arise and lead you askew
If we take the statement: "All dogs go to heaven. Victor is a dog; therefore, Victor will go to heaven." Assuming we look at this from secular point of view, the statement "all dogs go to heaven" is false because heaven doesn't exist; however, the argument that "Victor will go to heaven" is valid regardless of whether the reader is religious or not because, with regards to determining the validity of an argument, we are assuming that all dogs will go to heaven.
I guess the same thing would apply to "Victor is a dog"? Even if we know that Victor is actually a guinea pig, which would render this premise false, the argument is still technically valid based on what's provided to us because we HAVE to accept both premises as true. #help
I think it would be useful to apply the technical term 'soundness' here in place of truth. In formal logic and philosophy, an argument is sound if it is valid and the premises are true. This is for the LSAT and most of us don't care so much about the philosophical underpinnings of these relationships, but with the technical term people could do more personal research about arguments without being confused when they come across the term 'sound'.
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47 comments
Validity does not equal to truth. However, if all premises are true then the conclusion must be true. This makes an argument valid. An invalid argument depends on the truth of the premises.
so its still a good rule of thumb to not use your outside knowledge on the test?
“I think we all know the definition of truth and yes, it’s what you think.”
… phew
thank you to freshman me for wanting to be a philosophy major instead of a polisci major
If you're struggling with the information clicking, I would recommend watching again. The biggest point of this is that the reasoning is the most important thing when trying to determine if something is valid. Wether it is true or false doesn't necessarily matter because we aren't looking at most arguments from a real world lense anyways.
The plans for a building cannot be "true" or "untrue." They can, however, be structurally sound (valid) or structurally unsound (invalid).
Now, I tell you I'm going to build a house in Wonderland. I show you the blueprint. It is mathematically and structurally perfect—i.e., valid. If Wonderland were real, it would work flawlessly. And that validity is totally irrelevant to the "truth" of my premises, being that Wonderland is a real place I can build a house in.
How I am understanding this is even though the premises can be false, as long as the premises match the conclusion, it is a valid argument. You aren’t looking if the actual claims are “true” or factually correct. You are looking at the form of the argument and if the premises support the conclusion. If it does, then it's a valid argument.
Pls correct me if I am wrong.
Put differently, Validity means the premise logically supports the conclusion. (The math makes sense.)
To tie it back to subsets/supersets: an argument is valid if the set of all universes where its premises are true is a subset of the set of all universes where its conclusion is true. So the premises' truth is sufficient for the conclusion's truth, and the conclusion's truth is necessary for the premises' truth.
What happens if we are asked to take a case on in the real world and there are false premises that support the validity of the argument you're trying to make. Should we lie to juries that we are giving them true premises when giving false ones while obscuring true premises that harm the validity of our argument? How do we decide if the ends justify the means? Doesn't that mean we have an interest in being dishonest to people? Surely most other people conflate truth with validity.
wouldn't that lead to advocating for a position based on false premises in the real world, leading to being unethical?
so basically, your job isn't to decide whether the statements are true or false. Instead, you're focused on analyzing the structure of the argument to determine if it's logically valid.
What I got from this is that technically with each scenario we are operating within a closed universe that functions from different 'truths' each time?
I think the technical descriptions / the deep dives make me more confused honestly
Whether a claim is false in the real world or not does not matter because the reasoning of the argument determines whether it's valid or invalid.
I suggest rewatching the video. Initially, when I first watched it, I questioned myself because, like some of you in these comments, I was told to leave my real-world knowledge outside. That still applies. You just have to assume a claim is correct if it's a valid argument.
I remember at the beginning they told us we should not use outside knowledge for the test. Are we supposed to use outside knowledge for this concept?
#feedback
Basically when dealing with truth we are dealing with how the premises and conclusions make sense and see whether or not the argument has holes ( aka what assumptions can you make).
When dealing with validity we are just making sure everything is consistent , if not then it becomes invalid.
If an argument is valid, it means the argument is logically correct (The premise supports the conclusion and does not contradict one another.) Even though the premises are false, it can still be a valid argument.
The sufficient condition's presence guarantees the outcome of the necessary condition. Is that the relationship? The necessary condition can not happen until the sufficient condition is established, correct?
Maybe I missed it in the video, but for me it is also important to understand that just like a valid argument can have false premises, an invalid argument can have true premises.
Important to be on the lookout for this. Just because the premises and conclusion of an argument are all true does not guarantee the validity of the argument. If I told you that:
A. cats are mammals
and
B. siamese is breed of cat
then
C. Burmese cats are mammals
All these things are true, but the logic of the argument is flawed and therefore invalid.
If I am taking the LSAT after August 2024 is it necessary that I watch all these videos on formal and informal logic? Since we won't be doing the logic games?
Is it even worth reading all of these passages before continuing onto exercises and practice tests again after the diagnostic? I feel like I am reading a bunch but am not able to apply any of it right after learning about it.
It is really freeing to not assess whether or not something is true and instead consider if something is valid or not. It allows you to just assume the test is giving you enough baseline for knowledge and reject assumptions that could arise and lead you askew
Okay, so just to check my understanding here.
If we take the statement: "All dogs go to heaven. Victor is a dog; therefore, Victor will go to heaven." Assuming we look at this from secular point of view, the statement "all dogs go to heaven" is false because heaven doesn't exist; however, the argument that "Victor will go to heaven" is valid regardless of whether the reader is religious or not because, with regards to determining the validity of an argument, we are assuming that all dogs will go to heaven.
I guess the same thing would apply to "Victor is a dog"? Even if we know that Victor is actually a guinea pig, which would render this premise false, the argument is still technically valid based on what's provided to us because we HAVE to accept both premises as true. #help
I think it would be useful to apply the technical term 'soundness' here in place of truth. In formal logic and philosophy, an argument is sound if it is valid and the premises are true. This is for the LSAT and most of us don't care so much about the philosophical underpinnings of these relationships, but with the technical term people could do more personal research about arguments without being confused when they come across the term 'sound'.