It really is quite simple. A belief is "any proposition which we hold to be true". You cannot, as a voluntary act of will, simply "decide" to hold a given proposition as true. You can choose to SAY you hold a given proposition as true, you can even choose to ACT as if you hold a given proposition as true, but you cannot simply "choose" what propositions you accept and what propositions you reject. They are a result of evaluation, perspective and experience - not of simple, voluntary will.
This paragraph demonstratively establishes that beliefs are chosen. As I've stated elsewhere, they aren't only chosen. So, not an either-or proposition. But even accepting of that proposition is a choice. The whole thread strikes me as a discussion that demonstrate beliefs are chosen. You decide to validate an assessment or reject it, or parse it, or whatever. You/we are choosing this in a continuous process of visible dialogue, that is this thread.
This quote says 'I cannot choose what propositions I accept and what propositions I reject. (Instead) it is a result of evaluation, perspective and experience.' The evaluation part is the choosing among a set of judgments and/or beliefs. Perhaps, it is purely (and only) semantical in how the terms are being conveyed. I choose to believe it is not entirely semantical and invite further discussion, but reserve the right to choose to reject my self imposed belief that it is not entirely semantical.
Perspective can and will be updated based on the beliefs I choose to accept (or reject).
I would gladly provide an example (already have in this thread), but I honestly cannot think of a plausible example where beliefs are not chosen. Especially when realizing that some beliefs may be (knowingly or unknowingly) mistaken.