#18 - It was once thought that pesticide TSX-400 was

[Dancingbambarina]

Hey Dancing,

This is a principle question, which means the answer choices are general ideas which could be applied to the argument. So, when the answer choice says "two pesticides" it doesn't necessarily mean Envirochem and Zanar, it means 2 out of the 3 pesticides we're discussing here.

The author's conclusion is that only 2 outcomes are acceptable:
1. E and Z are banned (along with TSX which is already banned)
2. TSX is legalized (along with E and Z which are already legalized)

So we need an answer choice that would make sense with either of those options. In answer choice (D), "one" can mean any of the 3 pesticides and the principle still holds true. We can test this by applying it to the two outcomes the author finds acceptable.

1. In the first, all 3 pesticides are banned. Why? Because one pesticide should be legal and the other illegal only if the former (the legal one) is less harmful than the later. Well E and Z are not less harmful than TSX, so under this principle all 3 pesticides need to be banned.

2. In the second outcome option, all 3 pesticides are legalized. Why? For the same reasoning above - but this time we're legalizing all 3 instead of banning all 3.

"the former" in the principle is just a grammatical reference to a legal pesticide, while "the latter" refers to the second option listed in the answer choice, the illegal pesticide. It's not talking about E/Z/ or TSX specifically, it's referring to which pesticide(s) are legal versus illegal.

Hope that helps!

Thank you for your help Dana.

Surely an AND statement is negated as OR? How if the contrapositive is met is this:"One pesticide should be legal and another illegal" NOT "both can be illegal or legal"?


Thank you so much

[Dana D]

Hey dancing,

You're asking two different things here. If you have an "AND" conditional, it looks like this:

Only people over 35 and born in America can be president.

President 35 & born USA

The contrapositive would be:

35
or President
born USA

So yes, the contrapositive is an "OR" statement because there are two sufficient conditions that must be met to be President - missing either condition would mean you cannot be President.

However, that is not what's happening here. "One should be illegal and the other illegal" are not two separate sufficient conditions - it's all one idea. The state of the world should be that "one pesticide is legal and the other illegal ONLY IF the former is less harmful to the environment than is the latter." The conditional relationship is between the ideas before and after the "only if."

legal pesticide less harmful than illegal pesticide 1 legal 1 illegal

Hope that helps!