It’s subjective for past events, and a mix of subjective and objective (depending on your model of determinism and randomness) for future events. For most cases, it’s simplest and gives the right answers to treat it as subjective always.
Think of it as not “chance that something happened”, but “my level of belief in what happened”. What happened, happened—there’s no probability there, no range of possibilities. But you don’t have access to truth, only to your limited observations (including second-hand observations, which themselves are suspect). Bayes’ rule is a way to incorporate a new observation into the range of possible truths which fit your previous observations.
It’s subjective for past events, and a mix of subjective and objective (depending on your model of determinism and randomness) for future events. For most cases, it’s simplest and gives the right answers to treat it as subjective always.
Think of it as not “chance that something happened”, but “my level of belief in what happened”. What happened, happened—there’s no probability there, no range of possibilities. But you don’t have access to truth, only to your limited observations (including second-hand observations, which themselves are suspect). Bayes’ rule is a way to incorporate a new observation into the range of possible truths which fit your previous observations.