Rousas John Rushdoony, Systematic Theology, Volume I, Vallecito, California: Ross House Books, 1994, p.174
"One of the most absurd and yet common of all heresies is subordinationism. Subordinationism places one or two persons in the Godhead on a lower level than another. This is the subordination of persons. Usually, it is the Son or the Spirit or both who are subordinated to the Father. An implicit Unitarianism is usually in the background. In the Joachimite heresy, the Father and Son were subordinated to the Spirit. From Marcion to the present, more than a few have down-graded the Father, as supposedly representing law as against grace (the Son), or love (the Spirit)."