#11- One approach to the question of which objects discussed

[Adam Tyson]

Absolutely, Dylan - the author did fail to connect the most powerful theories to the majority of theories that are purely theoretical. The test makers could have given us an answer that made that connection for us, and it would have helped. But they didn't, and instead they focused on the other gap in the argument, between theory and reality. Connecting those two ideas also helps, and that's what we need for a good Strengthen answer - some help.

Sometimes there's more than one good prephrase, and we may be looking for one kind of answer and not find it, in which case we have to try looking for another.

[CJ12345:]

Hi, powerscore
I read all the posts but still a little bit confused. I think I will try to write the FL based on my understanding. Could you take a look and see if they are correct?
The last sentence says:
P: solely on theoretical grounds
C: (real --> explanatorily powerful theory) is incorrect, which means real --> ~explanatorily powerful theory.
Now, my goal is to find an AC that matches this premise and conclusion.
the correct AC B is saying: solely on theoretical grounds --> ~real
This AC does not match the stimulus's premise and conclusion as I stated above. why it is correct answer?

[Jeff Wren]

Hi CJ,

The first part of the last sentence in the stimulus, which you correctly identified as a premise, is "most scientific theories contain entities posited solely on theoretical grounds." You may have left out the "most scientific theories" part in your diagram just for shorthand, but it is important to the argument, so I just wanted to mention this.

In other words, the fact that most scientific theories contain entities based solely on theoretical grounds is going to be a serious problem for an approach that designates objects as real based on the most explanatorily powerful scientific theory (especially when combined with Answer B which states that entities based only on theoretical grounds should never be designated real).

The second half of the last sentence states the conclusion of the argument, which is that this approach is flawed. Your first diagram should be a double arrow, as the words "all and only" in the first sentence of the stimulus creates a biconditional, similar to the words "if and only if."

Your comment "which means real --> ~explanatorily powerful theory" appears to contain a logical error. Stating that a conditional statement is incorrect does not mean that the sufficient indicates the opposite necessary condition.

For example, the statement "If I have a candy bar, then I must have a Snickers" is not actually true in the real world. However, that does not mean that "If I have a candy bar, then I must not have a Snickers" is correct.

Lastly, this a strengthen question (due to the words "most justify") rather than a Justify question, so your goal is to strengthen the argument in any way possible.

Answer B links the premise that most scientific theories contain entities posited solely on theoretical grounds to the idea of those never being designated as real, which supports the argument's conclusion that an approach which relies on designating objects as real based on the most explanatorily powerful scientific theory is flawed.

[Icyzhang]

Hi CJ,

The first part of the last sentence in the stimulus, which you correctly identified as a premise, is "most scientific theories contain entities posited solely on theoretical grounds." You may have left out the "most scientific theories" part in your diagram just for shorthand, but it is important to the argument, so I just wanted to mention this.

In other words, the fact that most scientific theories contain entities based solely on theoretical grounds is going to be a serious problem for an approach that designates objects as real based on the most explanatorily powerful scientific theory (especially when combined with Answer B which states that entities based only on theoretical grounds should never be designated real).

The second half of the last sentence states the conclusion of the argument, which is that this approach is flawed. Your first diagram should be a double arrow, as the words "all and only" in the first sentence of the stimulus creates a biconditional, similar to the words "if and only if."

Your comment "which means real --> ~explanatorily powerful theory" appears to contain a logical error. Stating that a conditional statement is incorrect does not mean that the sufficient indicates the opposite necessary condition.

For example, the statement "If I have a candy bar, then I must have a Snickers" is not actually true in the real world. However, that does not mean that "If I have a candy bar, then I must not have a Snickers" is correct.

Lastly, this a strengthen question (due to the words "most justify") rather than a Justify question, so your goal is to strengthen the argument in any way possible.

Answer B links the premise that most scientific theories contain entities posited solely on theoretical grounds to the idea of those never being designated as real, which supports the argument's conclusion that an approach which relies on designating objects as real based on the most explanatorily powerful scientific theory is flawed.

Hi Thank you so much for your answer. I have no question about this question specifically. But I have one concern regarding one sentence in your post "Stating that a conditional statement is incorrect does not mean that the sufficient indicates the opposite necessary condition." I wonder how should this be understood. I read this sentence on the Bible "to attack a conditional statement you must show that the necessary condition is not actually necessary for the sufficient condition to occur.", which in my understanding, to attach A --> B, the correct way is to show A --> Not B. Could you please help me where did I get wrong here? Thanks!

[Jeff Wren]

Hi Icyzhang,

You wrote:

I read this sentence on the Bible "to attack a conditional statement you must show that the necessary condition is not actually necessary for the sufficient condition to occur."

This is correct. To attack a conditional statement, you want to show that the term that was considered the sufficient condition in the conditional statement can occur without the term that was considered necessary occurring.

For example, let's say that I wanted to attack the following conditional statement:

If someone lives in the United States, then that person lives in Texas.

This could be diagrammed:

U.S -> Texas

To attack this statement, I only need to show one person who lives in the United States, but does not live in Texas, such as John Smith lives in the United States, but does not live in Texas.

However, this is not the same as showing:

U.S -> Not Texas

That diagram would mean:

If someone lives in the United States, then that person definitely does not live in Texas.

This is not correct. By showing that a person can live in the United States without living in Texas, I've only disproved the original conditional statement. This does not create a new conditional statement that states the opposite of what the original statement said.

By showing that a person can live in the United States without living in Texas, I've only shown that living in Texas is not necessary to living in the United States, but living in Texas may (and factually is) still compatible with living in the United States. In other words, someone living in the United States tells us nothing about whether or not that person lives in Texas.