By saying “we’re all mad here,” the Cheshire Cat reframes Wonderland as a realm whose rules invert those Alice expects. “Madness” is not mere insanity but a different, internally consistent logic that runs on paradox, circular proofs, and category slips. The Cat’s mock-syllogism—dogs growl when angry and wag when pleased; the Cat does the opposite; therefore he is mad—parodies empirical reasoning and shows how conclusions can feel valid while resting on arbitrary premises. His earlier exchange about destination—if Alice doesn’t care where, any way will do—likewise reduces purposeful travel to a tautology, exposing how goals give meaning to direction. The line also answers Alice’s ongoing complaint that “all the creatures argue,” converting her frustration into a principle of navigation: expect contraries, and you won’t be surprised. “You can’t help that” suggests inevitability; Wonderland’s madness is environmental and participatory. By admitting Alice into a community defined by nonstandard logic, the Cat prepares her for the Hatter’s perpetual teatime and the Queen’s capricious croquet, where etiquette and law operate like the Cat’s grin—persisting even when substance disappears.