Furthermore, and as alluded to above, within the doxastic conception of probability we can make a further subdivision into subjective and objective doxastic attitudes. The defining characteristic of an objective doxastic probability is that it is constrained by the demand that the beliefs are calibrated to some objective fact or state of affairs, or else by further rationality criteria. A subjective doxastic attitude, by contrast, is not constrained in such a way: from a normative perspective, agents are free to believe as they see fit, as long as they comply to the probability axioms.