#23 - To predict that a device will be invented, one must

[moshei24]

I see why (B) works. But why doesn't (C)? Is it because it's not actually challenging the hypothesis, but rather it's challenging the idea of predicting an invention in the first place? It agrees that the hypothesis is correct, but given that, the idea of predicting in the first place is impossible. Or is it not even an hypothesis in the first place?

Please clear this up for me. Thanks so much!

[Nikki Siclunov]

I think you got this right. The author never argued that the hypothesis of predicting an invention has a false implication. Rather, the claim is self-contradictory given what it means to "invent." I'm also not sure you can describe the idea of predicting an invention as a "hypothesis."

[Barcelona10]

Dec. 2009, LR3, #23, Method of Reasoning: Predicting inventions:

I narrowed the answers down to B,C, and E. I always try to approach these questions with the mentality that one of the instructors at Powerscore recommends that one answer will always have to distinctly better than the others.

In this case, I'm having trouble seeing why B is better than C and E. E I thought was the best because it describes the logic of the stimulus' pointing out that we cannot predict inventions because if we did, the invention already took place. What is wrong in my thinking? C was one I held onto because the stimulus does seem to say that predicting an invention would mean, or imply, inventing itself, and consequently, no actual prediction taking place. I understand why E is correct now, but during the test, the correct answer did not pop out from the rest. How do you approach this question?

[Jason Schultz]

Hello,

At first glance, I believe you mistyped in your second to last sentence. You say that E was the correct answer, but B is actually correct.

Your analysis of the author's logic is correct. In the stimulus, they effectively state that the act of predicting and invention necessarily includes the act of inventing, and so you are no longer predicting the invention because you just invented it. The key is that inventing is the creation of an idea.

But the author does not extend this logic to "any event" as answer choice E does. For example, I can predict rain tomorrow, but this in no way implies that it has already rained on that day.

With respect to C, you correctly note that predicting an invention implies inventing it. But answer choice C claims the author was indicating the "falsehood" of the implication, which is not what they have done. The author would say that the implication is true.

Answer choice B is the best, as the author refers to the definitions of "invent" and "predict" to conclude that inventing is a necessary part of predicting, but predicting by definition cannot include things which already occurred.

[est15]

Hi, I don't really understand why C is incorrect. It sounds like the author is trying to counter the hypothesis of how predicting a device works (first sentence) by saying that the hypothesis can never be correct due to a self-contradiction (second sentence). Both B and C looked valid to me.

[David Boyle]

Hi, I don't really understand why C is incorrect. It sounds like the author is trying to counter the hypothesis of how predicting a device works (first sentence) by saying that the hypothesis can never be correct due to a self-contradiction (second sentence). Both B and C looked valid to me.

Hello est15,

Well, "definition" is closer to what is in the stimulus, since a definition of "inventing" is given. Answer C is tempting, but: "false implications of a hypothesis" might be something more like, "If Johnny jumps out of a tenth-story window, he'll happily float to the ground" having the necessary implications that Johnny will not go splat on the pavement, which are false implications, unless Johnny is made out of helium or something and is not subject to the laws of gravity. Answer B is narrower, about the definition of "inventing" being violated, which matches the stimulus nicely.
But yes, C is tempting. In overcoming tempting answers, one has to read the stimulus and answers closely, to get the best match.

Hope this helps,
David

[JSLSAT]

Hi!

Quick question - could someone just clarify the argument a little for me? Specifically the last premise.

Premises:
- Predicting an invention means developing a conception of the invention (functions & consequences)
- Inventing means developing a detailed conception
- One cannot predict what has already taken place

Conclusion:
- "Predicting an invention" is self-contradictory

Wouldn't the third premise be better if it read "one cannot INVENT what has already been conceived"? I thought if you predict something, it has yet to take place; but you can't invent something that was already predicted. So how is it true, or even relevant, that "one cannot predict what has already taken place"?

Thanks for the help!

[Adam Tyson]

JS,

Certainly your proposed replacement premise captures what the author here is implying, and might be even more to the point if it said "one cannot invent was has already been invented". While that is an accurate paraphrase of what's being argued, I don't know that it makes the argument any better, especially since the author is trying to argue that "predicting an invention" is a self-contradiction. Since the concept oi "prediction" is crucial to his argument, I think it makes good sense to bring that concept up again in the third premise.

Regardless of which version of this author's argument would be better than another, on the LSAT we are tasked with dealing with the argument we are given, good or bad. Let's not lose sight of that goal and get lost in the weeds! If you see the wording of that third premise as being flawed, then you might be better prepared than others to weaken the argument, or strengthen it, or identify the flaw, or any number of other things. It's okay to pick apart an argument, if doing so helps you to better approach the question stem, prephrase your answer, sort into losers and contenders, and then pick the best answer. Beyond that, though, there's not much point to analyzing the arguments with an eye towards improving them - most arguments on this test are bad arguments, so you could spend a lot of time imagining ways to make them better. That seems like a potential waste of a lot of time and energy to me, though. Instead, focus on how to quickly and efficiently tackle the task at hand, which is to select the best answer of the bunch and move on, quickly and confidently.

[JSLSAT]

Thank you for clarifying - and I completely understand.

I just don't understand the role that premise plays in the argument. It seems to define an aspect of "predicting" that would be better suited to their concept of "inventing" (i.e. you can't invent what you already conceived of while predicting the invention).

[Adam Tyson]

Here, the author defines predicting for us as developing a concept with details, but then tells us that inventing also means developing that detailed concept. In other words, in order to do this kind of "predicting", you have to first "invent" the thing you are "predicting". The confusion you are having over [predict vs. invent] is exactly the point of the author's argument - you can't predict an invention because the act of predicting requires that you actually invent the thing you are supposedly predicting! At that point, it's not really a prediction at all, but just an invention!

I hope that cleared it up some?