Facts and values
“The library recorded 100,000 visits last year” is a factual claim. “Longer hours will increase attendance” is a prediction. “Public money should prioritise people who finish work late” is a value judgment. Each can be discussed, but each needs different support.
For facts, examine definitions and records. For predictions, examine assumptions and uncertainty. For values, ask whose interests take priority and what trade-offs are acceptable. People can agree on the numbers while disagreeing about fairness; repeating the numbers may not resolve that disagreement.
Write an opposing view in terms its supporter could recognise before responding. You do not have to surrender your position. You are trying to avoid arguing against a claim nobody made. Identifying the real disagreement is itself progress.
Practice
Break down: “This plan costs too much, nobody will use it, so we should reject it.”
Reference response
Fact: what does it cost and what is included? Prediction: what supports the usage forecast? Value: what benefit would justify the cost, compared with which alternative?