I care about what it’s rational to believe before sorting the problem out. Why? Because many disagreements that we regularly face are not so easily resolved and it is precisely those that are the most interesting and challenging disagreements to handle. For example: “I thought we should pay down our mortgage, but my sister said it’s better to save for retirement.” “I really think I should marry him but my parents think otherwise.” “My cardiologist thinks I should put off having my valve replacement surgery, but the cardiac surgeon said that the operation is called for now.” I suggest that there might be something for us to learn from simple cases of disagreement that we might - no, we should - apply to the more complicated and important disagreements with which life is brimming.
It seems obvious to me – a fact of rationality itself – that the awareness of the disagreement of the second clock must dramatically reduced the confidence that one rationally had in initially believing that it was 7 am.
In Part 2, we’ll explore some more complicated disagreements, but this is an important time to chime in if you think that my conclusion is mistaken. I’ll repeat it one more time: the instant you become aware of the significant and mutually exclusive disagreement of the second clock, you have a very good reason to drop your belief that it’s 7 am. You suddenly have a very good reason to doubt that you can tell anything reasonable about the time, except that maybe, it’s morning, and that'll just have to do until you gather information that will settle the question. I think that if you agree with me here, you’ll have to admit that disagreement ought to have a much greater impact upon the confidence we have in our beliefs than it seems to have. Join me in the rest of this series on disagreement to see if I’m right, or if you disagree!