Read these only after you have written your own three sentences. Two of the paragraphs are good, one is not. The question is not which side is right — the lesson does not settle that — but what a paragraph has to do to count as an argument at all.

Model A — keep the binary, move the line

The board should keep the binary predicate. My reason keeps bivalence, and it keeps it for this domain: certification is a claim against Chisso, and a claim is something a person has or does not have — a court can move the line, but it cannot issue a status of 0.62, because nothing in the machinery of rights and remedies knows what to do with one. I am not saying bivalence is right everywhere; fuzzy logic runs the brakes on my car and I am glad of it. The price I pay is the plaintiff just below the threshold whose marginally worse neighbour is certified, and I owe her more than “lines have edges”: I owe her a line that is defended by what it is for, and a procedure for redrawing it that does not take fifty years. And I know the choice of instrument is not something my logic proves; it rests on what I take a court to be.

What it does: names the side; names the law it keeps and confines the claim to the domain; names the price and admits it is a debt; says what grounds the choice, and that it is not a logical result.

Model B — go degree-valued

The board should adopt a degree-valued predicate. My reason gives up bivalence, and it gives it up here, not everywhere: the harm at Minamata arrived as a dose-response curve, and a yes-or-no status is not a discovery about that curve but a line drawn across it — the same line I called drawn, not found, at the Vasa, and I am carrying that commitment across rather than revising it. The price I pay is that I now owe an account of where the graded instrument stops: compensation can be scaled to degree, but a criminal verdict cannot, and if I cannot say what makes the difference then “go fuzzy” is a slogan. My answer is that certification is money and care, which come in amounts, while guilt is a status, which does not — and I accept that this puts the binary back one step, not away.

What it does: the same moves on the other side. Notice that both good paragraphs agree that the choice is not won by a logic, and both confine their claim to a domain. That is where the case lives.

Model C — a paragraph that does not count

The board should obviously go fuzzy, because fifty years of lawsuits prove that classical logic is wrong: the world just isn’t black and white, and non-contradiction is an old Greek idea that quantum mechanics has already refuted. With fuzzy logic a patient can be 70% likely to be a Minamata victim and get 70% of the money, which is fairer, and anyone who insists on yes-or-no is simply being illogical.

What goes wrong:

  • “Classical logic is wrong” is the slide the lesson warns against: the binary is painful here, and the paragraph turns that into a claim about logic everywhere. Position B needs no such claim, and cannot defend it in one sentence.
  • Wrong law. Bivalence is what is at issue at Minamata; the paragraph reaches for non-contradiction, and for quantum mechanics, which the lesson explicitly leaves disputed.
  • Probability. “70% likely to be a victim” reads a degree of truth as a chance. Fuzzy logic says the predicate applies to degree 0.7, with nobody unsure of anything — that is the whole point of the instrument.
  • No price. “Fairer” costs the writer nothing; it does not say where the graded predicate stops, or what happens to guilt and personhood.
  • “Illogical” for the other side. Whoever keeps the binary is not reasoning badly; they are choosing an instrument — and the choice of instrument is not a logical result. Calling it illogical is judging one logic by the standards of another, which is the mistake the lesson’s floor question exists to catch.

The checklist

A paragraph counts as an argument when it:

  1. names a side;
  2. gives a reason that names the law kept or given up, and says whether the claim is about this domain or about logic everywhere;
  3. names the price the side pays, in the writer’s own words;
  4. says what grounds the choice of instrument — or at least admits that no logic wins it on the merits — and answers, or states, the strongest objection from the other side.

Model C fails 2, 3 and 4. Go back to your own paragraph and mark it 1–4.