Hume’s gap, Hume’s law, Hume’s guillotine, the “is-ought” problem, the naturalistic fallacy–they’re all phrases for the same observation: That a moral prescription (an “ought” statement) cannot be derived from an empirical observation (an “is” statement) by itself. The gap that you ought to bridge, if you want other people to clearly see your reasoning and thus evaluate your claim more accurately, can be done with the use of an “if” statement, which will delineate a specific goal or intention and which provides the avenue for empirical investigation. Which, astute readers will note, I just did with that exact sentence: “You ought to bridge the is-ought divide if you want your moral reasoning to be understood clearly because the ‘if’ will provide a logical avenue of investigation.” We could do a poll and ask which argument is more convincing: “trees produce oxygen, I need oxygen to breathe, and if I want to breathe, I ought not to cut them all down” or “trees occur spontaneously in nature, nature is good, therefore trees are good” and thus shed some light on whether my premise is accurate.
Of course, even that formulation assumes “I want my moral reasoning to be understood clearly” and so it carries a few weaknesses: If I am a charlatan, my actual moral reasoning is likely related to my immediate material gain, but being a charlatan I’d want to convince you my moral reasoning is something else, in which case my argument falls apart–the charlatan doesn’t want their moral reasoning to be clear, so they have no incentive to bridge the is-ought divide and instead pretend you can make it from one side to the other with a judicious application of creative thinking.
And so we jump feet first into moral skepticism, the intellectual quagmire in which I have been stuck waist-deep for a few years. My arms are outstretched, if any theorists from other moral schools care to grasp them in a bid to free me from my prison. I invite you to heave-ho and extract me from this intellectual quicksand in the comments, though I suspect my colleague Marcus will likely try sabotage your efforts.
All of which was a rather long-winded introduction to one of the more stark demonstrations of the is-ought divide I’ve seen in trans-antagonistic arguments: Society hates trans people, transition “cures” gender dysphoria but marks us as “trans,” therefore we should (somehow) get rid of gender dysphoria without transitioning. I’m not the first trans feminist to see this proposed to them, either–here’s Zinnia Jones: (emphasis original)