This is a tangent, but, it seems to me that our mental model of whatever problem is being discussed has multiple levels of information. Some things are stored directly as facts, but other things are inherent in the model contained in the brain. Seems like a reasonable argument could be made to include everything that falls out of that model as part of one’s beliefs.
Which means it could be reasonable to include all of those “negatives” (things that aren’t a valid part of the model) as part of one’s beliefs including your statement above.
When we say “accept as true”, I guess the next question is: does it have to be something previously considered and logged away? or can it be something that naturally falls out of a quick inspection of one’s model of the world? Where do you draw the line?