 Alternatively, one might argue that the obligation to participate does not trace to the benefits we receive from the efforts of previous research participants. Rather, the obligation is to the overall social system of which clinical research is a part (Brock 1994). For example, one might argue that individuals acquire this obligation as the result of being raised in the context of a cooperative scheme or society. We are obligated to do our part because of the many benefits we have enjoyed as a result of living within such a scheme.