Hume's point is not that facts are irrelevant — it is that facts alone never reach a verdict. Pick a dispute, then lay a bridging premise across the canyon and press Load test. Two different things can go wrong: a plank that doesn't reach, and a plank that reaches but can't bear weight.
1 · Choose a crossing
Is · the facts
Ought · the verdict
2 · Lay a plank across the gap
The canyon
Does it span? —
Logical fit: does this premise actually connect this fact to this verdict?
Will it hold? —
Defensibility: once you say the premise out loud, can you defend it?
No plank laidPick a bridging premise on the left. With nothing across, the argument simply stops at the edge.
WhyEvery moral argument that moves from data to duty crosses this canyon. The only question is whether the crossing is visible and inspectable or smuggled.