U članku se izlaže i tumači prva knjiga četvrtog sveska Peripaletičkih rasprava Frane Petrića. Ta knjiga nosi naslov: »0 principima prirodnih stvari« a Petrić u njoj podvrgava kritici Aristotelove principe fizike, odn. prirodne filozofije. Rasprava se centrira oko kritike prvih kontrarnih principa, oko kritike principa forme i lišenosti (privatio,steresis) i njima podmetnutog subjekta (hypokeimenon). U svojoj kritici Petrić pokazuje odmak od ideje peripatetičke fizike. On ne prati Aristotelova razumijevanje kontrarnih principa koji su uopće pretpostavka da bi se inteligibiliziralo kretanje. Petrić već unaprijed pristupa kretanju kao nečemu što se može racionalno dohvatiti i traži uzroke (a ne principe) kretanjem novonastalog bića. Pritom dolazi i do promjene u pojmu subjekta. Petrićeva kritika ukazuje na interes za empirijska istraživanja, iako ne doseže do pojma novovjekovne znanosti.The paper expounds and discusses the first chapter of the fourth volume of Frane Petrić\u27s Discussionum peripateticarnm. The chapter is entitled »De Principiis rerum Naturalium«. It is here that Petrić criticized Aristotle\u27s principles of physics, Le., natural philosophy. The discussion is based on the critique of the first contrary principles, the critique of the principle of form and privation (privatio, steresis) and their subject (hypokeimenon). In his critique, Petrić steered away from the idea of peripatetic physics. He did not follow Aristotle\u27s understanding of the contrary principles, themselves the conditions for making motion intelligible. Petrić a priori understood motion as something that may be rationally grasped and looked for the causes (not principles) through the motion of a newly created being. At the same time, there was a change in the notion of subject. Petrić\u27s critique pointed at the interest in empirical research, although it never reached the notion of modern science
