Is this an example of a sufficient assumption?

[ieric01]

Hey guys,

Is this an example of a sufficient assumption or a necessary assumption? (working hard increases your chances of getting rich)

Premise 1: To get rich you need to do a lot of work

Premise 2: People who work hard are able to do to the work necessary to become rich

Conclusion: Therefore, people who work hard are more likely to get rich.

Sufficient Assumption: Working hard increases your chances of getting rich.

[Robert Carroll]

ieric01,

I don't think that statement is a Sufficient Assumption or a Necessary Assumption.

A sufficient assumption makes the conclusion absolutely true. But that statement doesn't prove that people who work hard are more likely to get rich. So it's not a sufficient assumption.

A necessary assumption is something an argument needs in order to work. Because the conclusion of the argument is merely about a correlation, the cause-and-effect statement doesn't have to be assumed.

I think it's more useful to look at actual LSAT arguments in order to analyze sufficiency vs necessity of assumptions.

Robert Carroll

[ieric01]

Hey Robert, thanks for your reply!

It made a bit more sense but it still didn't clear out all the conceptual cobwebs in the way.

If you don’t mind, I’ll lay out my thought process for how I was thinking about this argument.

Love if you can help me spot where in my reasoning I went wrong.

Here it is:

I notice that…

There’s not a premise in the argument that says working hard increases your chances of getting rich.

The only premises we have is…

1. You need to do a lot of work to get rich. Eg: Deciding on the vehicle to get rich, making a plan, executing the plan, raising money possibly…
2. There’s a category of people (hard workers) who can do the work to get rich

Then, from these premises we get the conclusion: Hard work = a better chance of getting rich

The flaw I see is that…there’s nothing in the premises that covers the probability aspect of getting rich, namely that hard work increases your chances.

Q’s: So could you fix the logical structure of this argument by mentioning this probability aspect in the premises. Because if it’s true that working hard increases your chances of getting rich, then wouldn’t people who work hard be more likely to get rich (the conclusion) ?

[Jeff Wren]

Hi ieric01,

Your argument seems to be mixing several different ideas.

Premise 1. You need to do a lot of work to get rich.

This is a conditional statement, where "get rich" is the sufficient condition and "a lot of hard work" is the necessary condition. It could be diagrammed GR (get rich) -> AHW (a lot of hard work). So while doing a lot of hard work is necessary to getting rich according to this statement, it doesn't guarantee that one will get rich or even correlate with getting rich. In other words, it may take other things besides hard work, such as luck, skill, etc..

Premise 2. There’s a category of people (hard workers) who can do the work to get rich.

So this group has the capability of satisfying the necessary condition (a lot of hard work), but we haven't established that they actually have satisfied the necessary condition. Even if they had, it doesn't get us much closer to "getting rich."

Your conclusion is: "Therefore, people who work hard are more likely to get rich."

This statement is describing a correlation. If the conclusion is implying that people who work hard are more likely to get rich "than people who do not work hard," then this definitely hasn't been proven, even with adding your assumption: "Working hard increases your chances of getting rich." This is because the conclusion would be comparing two different groups of people who may have other characteristics besides hard work that makes it impossible for us to know which group would be more likely to get rich.

If your conclusion is implying that people who work hard are more likely to get rich "than they otherwise would have," then that seems to more or less restate your added assumption that "working hard increases your chance of getting rich." Of course, none of the other premises would really come into play.

[ieric01]

Hey Jeff!

Your break down of my argument was great!

It was very insightful and it also brought some interesting questions.

For instance:

For premise 1:

When you said... hard work doesn’t “even correlate with getting rich” ... do you mean there’s no correlation at all? Even if hard work is a necessary condition of success that we satisfied?

For premise 2:

You mention (and I'm paraphrasing), that even if the hard workers did do the hard work ... it doesn't get us much closer to getting rich.

Did this arise from the same assumption you made in Premise 1, that hard work doesn’t correlate with getting rich?

Finally, for the conclusion:

You state that if the conclusion was implying that hard workers are more likely to get rich "than they otherwise would have," none of the premises would come to play.

Does this mean I’ve made an ‘empty claim?” Because I’m stating something without evidence?

I look forward to hearing your thoughts!

[Rachael Wilkenfeld]

Hi ieric,

Jeff is pointing out that you are trying to draw conclusions that you haven't proven or provided appropriate support for.

To get rich you need to do a lot of work

R---->work

People who work hard are able to do the work necessary to become risk

WH--->able to work

Work is our required condition in the first premise. That means knowing that someone did work tells us it's possible they get rich, but doesn't really make it likely or unlikely. It just makes it possible.

For the second premise, it doesn't tell us anything about what does happen. It just talks again about possibilities. People who work hard CAN do the necessary work from premise 1, but we don't know that they do said work, and even if they did, we can't go backward from "doing the work" to getting rich. It's a mistaken reversal.

Your conclusion just isn't proven because you haven't given any premises about what is likely/unlikely. We don't know that other people also can't do the necessary work. You set out possibilities.

Typically conclusions from conditional statements won't be a likelihood. Conditionals are all about certain relationships and requirements.

Hope that helps!