aristotle and baptism

I like how RC Sproul summarizes Aristotle's illustration on types of cause ... and the thinking relative to baptism:

Aristotle identified various types of causes. His favorite illustration of the various causes involved a statue. He said a statue has several causes, several things that must be present for the image to take shape. First, he said, there has to be a material cause, which he defined as the material from which the statue is made. It could be a block of stone, a chunk of wood, or some other substance. He then identified the efficient cause, a person who changes the shape of the material and refashions it. For a statue, the efficient cause is the sculptor. Next there is the formal cause, a plan, idea, or blueprint that directs the alteration of the material. There is also a final cause, which is the reason for the statue. Finally, Aristotle identified the instrumental cause, which is the tool or means by which the change in the material is wrought. In sculpting his Pieta, Michelangelo could not just command the marble to take the shape he desired. He needed a chisel and a hammer. Those were the instruments by which the change in the marble took place. 

As Protestants, we say that justification is by faith alone. That little word by is critical to our understanding of how justification takes place. It does not mean that faith is meritorious and obligates God to save us. Rather, the word by indicates grammatically what we call the instrumental dative, which describes the means by which a thing comes to pass. So, to use Aristotle's categories, faith is the instrumental cause of justification, according to the Protestant view.