Beliefs come in degrees. Isolate each factor leading to your final degree of belief.
We can also ask questions about why people believe what they do and there are always multiple important reasons. Why does Bob believe in global warming? Because it is high status and it makes sense to him that gasses could trap heat. why is it high status? Because experts believe it. Why does it make sense to him? Because he heard it described, simplified, in a way that was internally consistent. Experts’ beliefs and the consistency of the story are both related to how likely the proposition about global warming is to be true.
Counterfactuals are helpful. What is the probability that global climate change is real? You have an answer. Now, imagine that one scientist changes his mind from this opinion to an extreme minority one that weather events have been flukes, or not unusual, or caused directly by an anomaly in the sun that is about t return to normal, or whatever. If you claim that that would have literally on effect on your beliefs, you will suffer from a line-drawing problem as you are asked about hypothetical scenarios in which ever more scientists defect from the scientific consensus. You would have to explain something like why 10% of scientists believing something is meaningless, but 10.0000001% isn’t.
The important thing is to not become misled by the fact that moderately different scenarios would result in your having, wholly appropriately, indistinguishably similar confidence. Very different scenarios leave one with much less confidence.
Likewise, you oughtn’t say there is no important relationship between a layperson’s belief and reality just because the relationship is attenuated by many intermediate steps and weak causal effects at each link in the chain.
Beliefs come in degrees. Isolate each factor leading to your final degree of belief.
We can also ask questions about why people believe what they do and there are always multiple important reasons. Why does Bob believe in global warming? Because it is high status and it makes sense to him that gasses could trap heat. why is it high status? Because experts believe it. Why does it make sense to him? Because he heard it described, simplified, in a way that was internally consistent. Experts’ beliefs and the consistency of the story are both related to how likely the proposition about global warming is to be true.
Counterfactuals are helpful. What is the probability that global climate change is real? You have an answer. Now, imagine that one scientist changes his mind from this opinion to an extreme minority one that weather events have been flukes, or not unusual, or caused directly by an anomaly in the sun that is about t return to normal, or whatever. If you claim that that would have literally on effect on your beliefs, you will suffer from a line-drawing problem as you are asked about hypothetical scenarios in which ever more scientists defect from the scientific consensus. You would have to explain something like why 10% of scientists believing something is meaningless, but 10.0000001% isn’t.
The important thing is to not become misled by the fact that moderately different scenarios would result in your having, wholly appropriately, indistinguishably similar confidence. Very different scenarios leave one with much less confidence.
Likewise, you oughtn’t say there is no important relationship between a layperson’s belief and reality just because the relationship is attenuated by many intermediate steps and weak causal effects at each link in the chain.