I don't know if I've ever seen someone say "accept this because it's the received view" ("received view" is the normal term for it, but not everyone knows what that refers to).
Rather, when people tell someone that something is the received view, as I did above, it's merely to educate someone about what the received view actually is. This usually occurs when it's clear that someone isn't familiar with what the received view is, and you want to help them so that they don't come across as uneducated about the field in their future discourse.
Re the questions they ask:
What is the criterion for something’s being 'the standard view in philosophy'?
The criterion is that either (a) it's the consensus held by a vast majority, and/or (b) it's a pedogogical standard, taught in the vast majority of relevant courses. (a) and (b) can both be the case, but sometimes (b) is the case for pragmatic reasons. For example, when you're first teaching students about the standard characterization of propositional knowledge, you just teach "justified true belief" and ignore the Gettier problems, because that's a far more advanced topic than you're going to tackle in an Epistemology 101 type course.
The distinction between facts and truth, and the idea that truth is a property of propositions, is going to be taught in every single intro-to-mid-level epistemology course by an analytic-oriented philosophy department.
The way one knows the above, by the way, is via familiarity with the field, familiarity with a wide swath of the literature in the field, including books used as textbooks, familiarity with philosophers, what philosophy departments set as their curriculae, etc. You gain that by being involved with that world, first as a student, especially if you've gone on to postgraduate work, and then as a teacher, as someone who interacts with philosophers at conferences/congresses, etc.
More fundamentally, however, you might ask why p‘s being an instance of “the standard view in philosophy” has anything to do with its truth.
As I explained above, it simply has to do with the truth of it being the received/standard view. Not knowing such a 101-level standard view immediately telegraphs to the person you're talking to that you have no formal education in philosophy. They know right off the bat that at best one is self-taught via the Internet, probably via message boards, Wikipedia pages, etc.
Standard views in philosophy” are temporally indexed: they change over time.
Sure, that's the case for many views. However, for others, such as the jtb formulation of propositional knowledge, they've been the received view since Plato.
So unless the person has a synoptic grasp of the whole history of philosophy,
Which anyone with a formal education in philosophy will have. Philosophy isn't like the sciences. You don't just learn the current status quo. You study the history of the discipline. There might be one or two schools that don't require a historical approach as a significant part of the curriculum, but they'd be extremely unusual.
One of the big reasons for this is that too much in philosophy is basically incomprehensible if you're not familiar with the field's history, if you're not familiar with the major works in the field going back to Plato. One can see the entire history of philosophy as akin to a massive, 2500+ year long message board thread--people are commenting on stuff that was said earlier in the thread, and posts thousands of pages into the thread can be unintelligible without knowing at least the landmark earlier posts. Philosophers generally write for other philosophers, which results in a dearth of explanatory contextual material--it's expected that you're already familiar with the background necessary if you're reading peer-reviewed journals, books published by academic presses, etc.
S believes that p at t, where “S” stands for “the set of people affirming the standard view” and t is some time . . .
When someone says that such and such is the received view, they mean at present. Otherwise they'd say that such and such
was the received view.
