 These three possibilities correspond to three classic responses to this regress of justification. Infinitists hold that the regress goes on forever, coherentists that it cycles back on itself, and foundationalists that it ultimately terminates. The proponents of each view reject the alternatives as unacceptable. Infinitism looks psychologically unrealistic, requiring an infinite tree of beliefs that finite minds like ours could not accommodate. Coherentism seems to make justification unacceptably circular, and thus too easy to achieve. And foundationalism seems to make justification arbitrary, since the beliefs at the end of the regress apparently have no justification.