Logical Reasoning

PT105 · S2 · Q4 An ingredient in marijuana known

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An ingredient in marijuana known as THC has been found to inactivate herpes viruses in experiments.

Conclusion (it can be concluded)

The use of marijuana can cause cancer.

Evidence

An ingredient in marijuana known as THC inactivates herpes viruses. And inactivated herpes viruses can convert healthy cells into cancer cells.

Evaluate

The premises give us a bit of a causal chain:

Use⇢ imbibe ⇢ inactivated ⇢ convert healthy MJ THC herpes cells to cancer

Goal

It's hard to know how to argue around this, since the conclusion is so weakly worded and the evidence made it sound pretty plausible.

Let's just use our usual Debate Mindset and hope that the correct answer shows us a door.

Given that .... THC (which is in marijuana) can do something that has been found to convert healthy cells into cancer cells,

How can we argue that ... the use of marijuana cannot cause cancer?

Which one of the following, if true, most seriously weakens the argument?

Several teams of scientists performed
Strengthens
By learning that the experiment in the evidence has been corroborated by other experiments, we're making the evidence more trustworthy and thus strengthening the argument.
0% picked this
Correct
The carcinogenic effect of THC
Why this is right
Given that .... THC (which is in marijuana) can do something that has been found to convert healthy cells into cancer cells, How can we argue that ... the use of marijuana cannot cause cancer? We can say, "Using marijuana doesn't cause cancer. Sure, THC by itself could cause cancer by inactivating herpes viruses, but when you use marijuana you don't just ingest THC. The carcinogenic (cancer-causing) effect of THC gets neutralized by the other ingredients in marijuana." We could look at this argument in a sort of Part vs. Whole fashion. Yes, one part of marijuana (THC) causes cancer. But that doesn't mean that ingesting the whole of marijuana causes cancer. After all, other parts of marijuana can neutralize the potential harm of THC.
Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.
69% picked this
When THC kills herpes viruses
Strengthens, if anything
This answer elaborates on the causal mechanism by which THC leads to cancer. If anything, by giving us a better understanding of how THC leads to cancer vulnerability, we're just strengthening this argument. This answer definitely isn't giving us any way to argue that using marijuana doesn't cause cancer.
15% picked this
If chemists modify the structure
No Impact: prevent herpes
We're looking for an answer that will help us rebut the conclusion. We were asking ourselves, How can we argue that ... the use of marijuana cannot cause cancer? This is talking about rearranging THC so that it can prevent herpes. So this isn't giving us any storyline by which someone who uses marijuana would be protected against the cancer-causing potential of THC.
3% picked this
To lessen the undesirable side
Unrelated to Goal
We need an answer that will help us argue that "the use of marijuana does not cause cancer, despite the fact that THC has been found to do something that can convert healthy cells into cancer cells". This is talking about giving marijuana to people who already have cancer, so it's just irrelevant to our goal.
13% picked this

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