Causal vs. Conditional?

[ieric01]

Hey guys,

I'm confused about how a conditional relationship is different from a causal one. So I decided to separate the two and first take a stab at defining what a conditional relationship means. I gave my own example. Be ruthless . Feel free to tell me if my head is on its shoulder or if it has fallen off. Thank you!


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A conditional relationship has two parts: A (our sufficient factor) and B (our necessary factor). If A happens, then B happens. When something is ’sufficient,’ it is enough to guarantee the occurrence of the necessary factor. In other words, the necessary factor is the logical consequence of the sufficient factor.

For example, let’s look at the following conditional statement:

“If Bob graduates from college, then his parents will buy him a new car.”

The first part “If Bob graduates from college” is our sufficient factor. The second part "then his parents will buy him a car a new car” is our necessary factor.

Of course, Bob graduating from college isn’t the ONLY factor that will guarantee he’ll get a new car. Perhaps his parents lose their money in a lawsuit or a recession hits. But in the LSAT, our job is not to question whether or not something is true, we just assume it to be. Our goal is to check for the validity of the argument, NOT the soundness of it.

Anyhow, let’s get back to our example.

Let’s think of some of the common ways the LSAT test writers will try to trick us.

Mistaken Reversal

In a mistaken reversal, you reverse but forget to negate as such:

"If his parents did buy him a new car, then Bob graduated from college.”

This is wrong because we can’t prove that Bob graduated from college simply from the evidence of his parents buying him a new car. Perhaps he didn’t graduate. And his parents bought him a car, so in the upcoming semester, he gets to class early and doesn’t fail again due to his tardiness.


Mistake Negation

In a mistaken negation, you negate but forget to reverse it as such:

“If Bob did not graduate from college, then his parents did not buy him a new car.”

This is wrong because we can’t prove his parents didn’t buy him a new car from the evidence of him not graduating from college. Although it’s entirely possible we just can’t prove it. In the absence of the sufficient condition, we can’t prove anything about the absence or presence of the necessary condition.


Contrapositive

To get the contrapositive, you flip and negate as such:

“If Bob’s parents didn’t buy him a new car, then he didn’t graduate from college.”

This is true. If the necessary factor didn’t occur, then the sufficient factor never happened in the first place.

[ieric01]

I've been at this for a while, trying to wrap my mind around it.

Surprisingly, I couldn't find a clear distinction between the two, so I came up with my own.

Is this correct?

What’s the difference between a conditional and causal relationship?

A conditional statement has a sufficient factor and a necessary factor. And is represented by an ‘If -Then’ statement as such: If A then B. However, we don’t care whether A causes B. We’re only concerned that if A happens, B happens. For example, if you press on the gas pedal, then your car will run. So, every time we hit the gas pedal, we expect the car to run. Now what CAUSES the car to run is none of our concern. It could be a multitude of things like the engine, how much gas you have in the tank, etc that causes the car to run.

A causal relationship has a trigger and an effect. When A happens, B must happen. However, if B doesn’t happen we can’t eliminate A as a cause. A could be a partial cause that along with other factors makes B happen. This is different than a conditional relationship where if A doesn’t happen, the relationship is immediately false.

[Dave Killoran]

Hi ieric,

Overall this is a good start. But, do you have any of our materials or are you in a course? Because we define the difference very clearly, and I'd like to refer you to that as a starter since it's definitive and adds dimensions that you haven't touched on.

Thanks!

[ieric01]

Hi Dave, I have the logical games bible book but I will look into the LSAT logical reasoning. Thanks!

[Jay]

Hello.

I understand the difference between causal and conditional, but can I apply the same contrapositive idea in causal relationship?

For example, if i were to have a causal relationship,

Increased Money Supply (IMS) caused Interest Rate to decrease (IRD).

then I would diagram as

Cause -> Effect
IMS -> IRD

Then, can I say

Not IRD -> Not IMS

also, for additional question, would Not IMS -> Not IRD be a mistaken negation?

and, Not IMS -> Not IRD be a mistaken reversal?

Thank you!

[Claire Horan]

If you have the coursebooks, you may want to review the sections called "Conditional Reasoning" in Lesson Two and "Cause and Effect Reasoning" in Lesson Three. Questions involving a causal relationship will usually ask you to weaken or strengthen the argument that the causal relationship exists, and you will do this by considering: (1) whether there might be an alternate cause for the effect, (2) whether the cause ever occurs without the effect, (3) whether the effect ever occurs without the cause, (4) whether it is possible that the supposed effect is actually the cause and the supposed cause is actually the effect, and (5) whether the data or evidence supporting the claim that the relationship is causal is trustworthy.

You will not use contrapositives to answer questions involving causal reasoning. This is because, in a strict causal relationship where the cause always leads to the effect and the occurrence of the effect always means the cause has taken place, you actually have a biconditional, where both are sufficient and necessary for each other. Take, for example, the statement that gravity causes objects to fall. If you diagrammed this like a conditional, you would diagram gravity objects fall. The contrapositive would be objects fall gravity. True enough. But, a mistaken reversal or negation is not mistaken in this case. objects fall gravity. That's also true in the situation where a cause has only one effect and the effect has only one cause (a 1:1 relationship). Gravity Objects fall. Also true. But how would this diagramming help you on a question that asked you to strengthen or weaken the argument? It wouldn't, so don't go there. Instead, use the approach described in the first paragraph of my post and in Lesson 3.

Lastly, it's important to note that sometimes arguments on the LSAT suggest a looser cause-and-effect relationship, as in "Smoking cigarettes can lead to/contributes to/is a risk factor for developing lung cancer." This looser relationship does not suggest that everyone who smokes will get cancer or that a nonsmoker cannot get lung cancer. I mention this last point just to remind you to read carefully!

Good question!