Johann Crell (1590-1633), a preminent figure in the history of Socinianism, contributed to a revised edition of the Racovian Catechism (1665). He is also the author of more or less accomplished, but nevertheless remarkable commentaries, on New Testament’s books. Among his theological works, De Deo et eius attributis (first published in 1630, and in 1668, in the Bibliotheca Fratrum Polonorum) is the most original and relevant. A trait of this writing worthy of being emphasized is Crell’s strong (and surprising in a Socinian) philosophical commitment, explicitly carried out in the first part of the book, concerning the existence of God. His argument shows a critical approach to the point of view of Aristotle and of Andrea Cesalpino about God and his relation to the world. The teleological approach, suggested by Crell, is in contrast with the Peripatetic one, although it retains a close relationship with the explanation of deliberative processes unfolded in the Nicomachean Ethic.