James H. Olthuis is an inter-disciplinary scholar in ethics, hermeneutics, philosophical theology, as well as a theorist and practitioner of psychotherapy of a kind he calls "Relational psychotherapy."
Olthuis studied under H. Evan Runner in philosophy at Calvin College, Grand Rapids, Michigan; then in theology at Calvin Theological Seminary; and finally in philosophical ethics at VU University, Amsterdam, where he received his PhD under André Troost. Olthuis analyzed and critiqued the works of G. E. Moore, his dissertation being entitled Facts, Values, and Ethics: A confrontation with 20th Century British Moral Philosophy.
Olthuis was a senior member at the Institute for Christian Studies, in Toronto from(1968–2004) and continues to hold an emeritus position there.