The aim of the paper is to propose an understanding of idealization in terms of Nowak’s unitarian metaphysics. Two natural interpretations of the procedure are critically discussed and rejected as inadequate. The first account of idealization is unable to explain why idealized factors cease to exert influence on the investigated magnitude. The second account of idealization solves this problem but does so at the cost of blurring the distinction between idealization and abstruction. Moreover, it faces the consequence that the process (...) of idealization instead of leading to a sharper understanding of phenomena will normally result in making the picture more and more probabilistic. I propose a third account of idealization in unitarian terms that solves all three problems. (shrink)