  Carnap (1945) distinguished between two conceptions of probability, arguing that both were scientifically important. His ‘probability\(_1\)’ corresponds to an epistemic notion, nowadays glossed either (following Carnap himself) as evidential probability, or as credence or degree of belief. This is contrasted with Carnap’s ‘probability\(_2\)’, which is the concept of a non-epistemic objective kind of probability, better known as chance.