 The second question is what facts are relevant to determining someone’s utility function. Everyone in the debate accepts that preferences provide evidence for the utility function, but there is disagreement about whether there may be other sources of evidence as well. Constructivists hold that an individual’s utility function is defined by her preferences—utility is “constructed” from preference—so there are can be no other relevant facts (discussed in Dreier 1996, Buchak 2013); this view is also called strong realism (Zynda 2000). Non-constructive realists, by contrast, hold that there are other sources of evidence about the utility function: for example, an individual might have introspective access to her utility function. This latter view only makes sense if one is a psychological realist, though one can pair constructivism with either psychological realism or formalism.