In jQuery the three functions show(), hide() and toggle() go together. Since this is not about showing and hiding - as you said - neither show nor hide nor toggle should be used.

In jQuery.ui.Widget the two functions enable() and disable() are shortcuts for _setOption( "disabled", bool ). I assume it would be insane to start renaming "disabled" to "enabled" as I suggested below. I still think it's more sane to set something to enabled = true instead of disabled = false (double negation) but since this is part of jQuery we can't change it.

Keeping all this in mind _setDisabled( disabled ) would be the most consistent solution in my opinion.