Bernard Lonergan's understanding of the developing subject is conceived concretely in terms of the broadening horizon of the subject towards a real apprehension of the human good, from particular good to the notion of value. I will argue that Lonergan's understanding of the developing subject is a complex phenomenon rooted in the self-transcending existential subject's freedom and apprehension of value, which precedes decision-making and which orients the course of one's personal development.   An analysis of Bernard Lonergan's understanding of the development of the subject reveals that he drew heavily from the psychologist Abraham Maslow. My main purpose is to retrieve Lonergan's insights on personal development by comparing to what extent his thinking is similar to and different from that of Maslow's. I will argue that although there are similarities in their thought, the perspectives they offer regarding human nature are reached from within very different horizons, and therefore their understanding of personal development, although complimentary, is foundationally different.   In the final chapter I offer suggestions for merging the two thinkers' thought in order to provide a more complete understanding of personal development which takes seriously considerations from both psychology and theology.