A Claim to Obviousness
The claim that something is obvious often means that the arguer simply doesn’t have the ability or perseverance to articulate that argument, and wants you to let them off the hook by just pretending that you both agree that it’s true. We do this sometimes because arguments are often built on other arguments, which are built on other arguments, etc. To support Argument A we might have to support all the arguments that come before it, which takes time and effort that we don’t want to expend.
Aphorisms
“If you don’t believe X, then I can’t help you.”