In hac dissertatione relationes mutuae inter actuales et potentiales rerum determinationes invesigantur. Aucor descriptionem quandam formalem proponit, quae determinationum harum et actualem et possibilem vim in mutationem rerum, quae illas possident, exprimere condendit. Litem quoque famosam, de potentiae ad actum habitudinem inter Aristotelem et Megaricos olim exarsam obiter tangit et modum, quo J. Hintikka hic “principio plenitudi¬nis” usus est, adumbrat. In dissertationis fine auctor opinionem propriam, quomodo notionis dispositionis ope et conditionalium irrealium idoneo usu difficultates in hac materia occur¬rentes solvi possint.

In this essay I investigate the interplay between actual and potential properties of a thing within an Aristotelian conceptual framework. A minimal formal treatment of such interplay is proposed, outlining the actual or possible causal impact of these properties with respect to the changes of a thing in question. I also mention the historically interesting controversy between Aristotle and the Megarians concerning the relationship between power and act, as well as Hintikka’s application of the Principle of Plenitude. The essay ends with certain suggestions for treating the problems of actual and potential properties by means of dispositions and contrary-to-fact conditionals.