Final answer:
Claiming something is true because "it should be obvious" is an appeal to common sense, which can be a form of unwarranted assumption and a fallacy of weak induction.
Step-by-step explanation:
Claiming that something is true because "it should be obvious" is really just an appeal to common sense. This type of argument is based on the notion that certain truths should be evident based on direct sense perception and shared understanding. However, when such a claim is presented without a solid evidence to support it, it becomes an unwarranted assumption and falls into the category of fallacies known as weak induction. Philosophers and critical thinkers caution against relying too heavily on what is deemed to be "common sense", as it may not actually represent a logical or empirical truth that can be supported by strong evidence or reasoned argumentation.