Weakening and Strengthening

[ebrickm2]

I'm familiar with the fact that an argument can be strengthened in a variety of degrees, from that of a hole-closing defender assumption to a gut wrenching suggestion of an alternative cause for a supposed cause-and-effect relationship.

What interests me more is how minor can these supports and weakens be? Words can be interpreted in a variety of ways, and some marginal (but still incorrect) answer choices may creep into your head as potential contenders (especially frustrating in the early questions of a logic reasoning section).

So if an argument was something like:

Sending people to the moon to collect rocks would advance our understanding of planetary origins. Thus, we should send a manned rocket to the moon to collect rock samples.

Pretty straightforward argument, right? Why should we send a manned rocket to the moon to collect rock samples? Duh, so we can advance our knowledge of planetary origins. All square, no problems.

So how could we weaken this argument at the fringes, what qualifies as barely touching this argument in either support or weakening?

What if we said it is no more expensive to send a manned rocket to space than to send a robot to collect samples? Does this affect our argument (I really don't know, I'm not being rhetorical).

How about these:

The costs to send a manned rocket to the moon have increased dramatically over the course of the decade.

The men who would be on the ship would be trained geologist, more adept at finding the correct stones that would advance our knowledge of planetary origins.

I hope you can see where I am going.

I don't know where the line is that determines that "well, you aren't strengthening this argument, or you aren't weakening this argument, you're more of an irrelevant time wasting, rage inducing option that is probably so irrelevant most would simply scoff at me, and yet you have tried to find merit in me type question".

Sorry for the tirade, but I just need to understand.

[giladedelman]

Thanks so much for the interesting question!

The big thing to keep in mind when we're dealing with strengthen/weaken questions is that it's all about assumptions. To strengthen an argument, we make one of its assumptions explicit. To weaken an argument, we either negate an assumption or attack it by offering a specific counterexample.

Your moon exploration argument is an interesting example. You wrote:

Sending people to the moon to collect rocks would advance our understanding of planetary origins. Thus, we should send a manned rocket to the moon to collect rock samples.

Pretty straightforward argument, right? Why should we send a manned rocket to the moon to collect rock samples? Duh, so we can advance our knowledge of planetary origins. All square, no problems.

Not so fast! I see a BIG assumption there: the argument is assuming we should advance our understanding of planetary origins. What if that's not true? Maybe it's a bad idea to advance our understanding of planetary origins. In that case, we definitely couldn't conclude that we should send a manned rocket over there.

So, if we were trying to weaken this argument, we might negate the assumption:

-There is no benefit to be gained by advancing our understanding of planetary origins.

Or, we might offer a specific counterexample:

- The costs of manned moon exploration greatly outweigh the benefits of any knowledge such a mission might obtain.

Does that make sense? The key is that strengthen/weaken questions are fundamentally about assumptions. There's not really any such thing as an answer choice that weakens an argument "at the fringe"; if it doesn't influence whether the conclusion can be properly drawn -- by validating or negating an assumption -- then it doesn't have any effect on the argument.

Was this moon exploration question from a real LSAT? If so, I'd love for you to let me know where I can find it. Then I could address it more in-depth for you.

[ebrickm2]

Thanks so much for the interesting question!

The big thing to keep in mind when we're dealing with strengthen/weaken questions is that it's all about assumptions. To strengthen an argument, we make one of its assumptions explicit. To weaken an argument, we either negate an assumption or attack it by offering a specific counterexample.

Your moon exploration argument is an interesting example. You wrote:

Sending people to the moon to collect rocks would advance our understanding of planetary origins. Thus, we should send a manned rocket to the moon to collect rock samples.

Pretty straightforward argument, right? Why should we send a manned rocket to the moon to collect rock samples? Duh, so we can advance our knowledge of planetary origins. All square, no problems.

Not so fast! I see a BIG assumption there: the argument is assuming we should advance our understanding of planetary origins. What if that's not true? Maybe it's a bad idea to advance our understanding of planetary origins. In that case, we definitely couldn't conclude that we should send a manned rocket over there.

So, if we were trying to weaken this argument, we might negate the assumption:

-There is no benefit to be gained by advancing our understanding of planetary origins.

Or, we might offer a specific counterexample:

- The costs of manned moon exploration greatly outweigh the benefits of any knowledge such a mission might obtain.

Does that make sense? The key is that strengthen/weaken questions are fundamentally about assumptions. There's not really any such thing as an answer choice that weakens an argument "at the fringe"; if it doesn't influence whether the conclusion can be properly drawn -- by validating or negating an assumption -- then it doesn't have any effect on the argument.

Was this moon exploration question from a real LSAT? If so, I'd love for you to let me know where I can find it. Then I could address it more in-depth for you.

Nah, I made the question up. I understand the concept of assumptions, I just get confused as to whether or not it really is an assumption, the language can be construed in different manners and lead to me thinking that it could probably address it if I pursue it in my mind.

I dunno, its just upsetting. I understand the relationship of premises to conclusions but I feel like it they are written in such a way that I may be able to use the information to support it when the answer choices tell me it doesn't and at least for superprep explanations they don't even dismiss it as off hand but it isn't necessarily, they assume it is!