2021 CSAT — Q31

Locate. This is a valid-assumption question (“most logical assumption”) — find the unstated premise the conclusion needs, and test it by negating it (if the argument collapses, the assumption is needed). The passage’s conclusion: judged each by its own light, no religion is wrong; judged by each other, none is right; so “all the world is right or all the world is wrong.” The reasoning treats each denomination’s verdict as self-enclosed.

Test (negation test). For that impasse to hold, the denominations must lack a common, unifying standard — each judging only from its own side, ignoring a shared human ground. Negate (c): if denominations did recognise the unity of man (a shared standard), the right/wrong question would not collapse into all-or-nothing. The argument’s impasse depends on the absence of that unity → (c) is the needed assumption.

Eliminate by anatomy. (d) gets the direction backwards — the passage says a man can be “a judge of his own religion,” i.e., he does understand it; “do not understand” inverts the text. (a) is out of scope — whether a man can live without a denomination is never the argument’s concern, a claim the passage never makes. (b) is out of scope too — a “duty to propagate” is a prescription the passage never invokes. The transferable rule: a “most logical assumption” is the premise that, if false, breaks the conclusion — here, the absence of a unifying standard among denominations. Key: (c).

“If everyone is left to be a judge of his own religion, there is no such thing as religion that is wrong; but if they are to be a judge of each other’s religion, there is no such thing as a religion that is right, and therefore all the world is right or all the world is wrong.” — the all-right-or-all- wrong impasse can only arise if denominations judge from within their own standard with no shared, unifying ground; that is the unstated premise the argument needs → (c). (d) contradicts “judge of his own religion” (men do understand it); (a) “no man can live without a denomination” and (b) “duty to propagate” are extraneous claims the argument never leans on.

The passage argues that religious right/wrong, judged denomination-by-denomination, dissolves into “all right or all wrong.” This relativistic impasse presumes that denominations do not share a common, unifying standard of judgment.

• (c) names that presumption: denominations ignore the unity of man (a shared human ground). Correct.
• (d) reverses the passage, which grants that a man judges (understands) his own religion.
• (a)/(b) are extraneous — living-without-religion and duty-to-propagate are not premises the argument uses.

Answer: (c).

The passage is a tight abstract syllogism, so the assumption hunt is about what makes the impasse possible. The all-right-or-all-wrong result only follows if there is no shared standard across denominations — each is sealed in its own verdict. (c) supplies exactly that missing premise. Worth noting (a close call): (c) is composed from the structure of the argument — the all-right-or-all- wrong relativism only holds if denominations share no unifying ground — rather than handed to you in a quoted line, so it is a more inferential pick. (d)‘s reversal and (a)/(b)‘s out-of-scope status, by contrast, are clean eliminations.