Summary: This study is an effort to think together, as it were, the upright posture of the human body, indispensable for the emergence of language, and spiritual uprightness (rectitudo), namely the action of «righting» (rectificatio) as an act of healing, in explicitating certain aspects of the Scriptural concept of parrhèsia. The author considers this concept in the fields of philosophy and theology (especially Bonaventurian) from antiquity to current scientific discourse on anthropogenesis. Without forgetting that parrhèsia as the courage of truth or as a manner of living (in the tradition of the Stoics and the Cynics) was first taken up by M. Foucault in his last lectures at the Collège de France, the author treats of parrhèsia as the posture of prayer in the Talmudic, Eastern Christian and Buddhist traditions., and as a posture of courage in the face of contingent events or uncertain times. All this not without examining the bending of the knee and the ambiguity of «standing upright», oscillating between arrogance and the clinical bending down towards the weak and the infirm.