Few the or etical insigh ts h ave em er ged from the extensive literature di scussions of pe titio pr incipii ar gument. In par ticular, th e pattern of petitio analysis has lar gely been on e of movem ent between the two sides of a di chotom y, th at of form and content. In this paper, I trace the basis of thi s d ichot omy to a du alist conce p tion of mind and world . I argue for the rejection of the form/conten t di chotom y on the ground that its dualist presuppositions gellerate a reductioni st an alysis of cer tain concepts which ar e cen tral to th e analysis of petitio argumen t. I contend, for exam ple, th at n o syn tactic relation can assimil at e within its analysis the essentially holistic n ature of a notion like justification. In this regard, I ex pou nd a form of dialectical criticism which has been frequently employed in th e philosop hical arguments of Hilar y Putnam. Here the focus of an alysis is upon th e way in which the propo ne n t of a position pr oceed s to explain 0 1' argue for his/h er own pa r ticula r theses. My conclusion poin ts to th e u se of such dial ectic within fu tu re analyses of petitio pr incipii.In re cent years, Putnam has ' exhibited a philosophical preoccupation with issues of unintelligibility , such as they rel ate to traditional problems in philosophy-reference, knowledge of other minds, etc. That there is a 'problem' of reference to which a 'solu tion' must be found is, according to Putnam , th e manifestati on of a deep m et aphysical impulse within us . T his impulse h as re sulted in unintelligible questions and mistaken inquiries in all th e major disciplines of philosophy, including inquiry into the informal fallacies.Putnaru' s proj ect is not on e of scep ticism, but is inste ad an attempt to recapture a historic al moment in our thinking, one which is prior to the * This pa pe r was written while the auth or was a Visiting Fellow affiliated with the Departme n t of Philosophy at Harvard Un ivers ity. The au thor wishes to ackn owledge her ind ebt edness to Hilary Putnaru , Har vard Un iver sity, for d iscussio n of a number of the issues addressed in this paper. T he au thor is also gra teful to a refer ee of thi s j ournal fo r conuneuts 0 11 an earlie r version of th is pap er.