One of the fundamental problems in the philosophy of psychology is to determine the relation between personal and subpersonal explanations of human behavior. The problem of determining the relation between the personal and subpersonal levels is called the “interface problem”. This paper has two goals. The first is to introduce the domestic reader to the interface problem from the perspective of the philosophy of psychology. The second goal is to show that insufficient focus on the interface problem and its potential (...) solutions can lead to uncritical and fallacious reasoning that can have significant consequences for particular debates in philosophy of medicine and philosophy of law. (shrink)