What is the background of the words "notitia," "fiducia," and "assensus" and how do they relate to the biblical notion of "faith"? The book Philosophical Foundations for a Christian Worldview (page 18) describes notitia, fiducia, and assensus as the three essential elements that make up the biblical notion of "faith." 

notitia is defined as "understanding the content of the Christian faith"

fiducia is defined as "trust"

assensus is defined as "the assent of the intellect to the truth of some proposition"

I am trying to determine what the background is for each of these three words along with what their origin, context, and usage is. Where did they first appear? What is their relationship to the New Testament or the Old Testament?
Origin - Loci Communes Theologici, 1521 A.D.

The words notitia, assensus, and fiducia applied to faith originates with the Reformers of the 16th Century. Martin Luther argued that saving faith or true faith is a fides viva, a vital or living faith (Sproul, 2010, pg.47). This concept was further explicated by one of Luther's contemporaries, Philip Melanchthon. In 1521 Melanchthon first published his work, "Loci Communes Theologici," which was the first systematic explanation of Protestant theology, and condensed the thoughts of the Reformers and defined notitia, assensus, and fiducia as the three essential elements of saving faith. It is he that codified what the scriptures had taught, and it was from Melanchthon's work that these words first appeared in the context of faith (Israel, 2007, pg.233).



Context and Usage

Rome feared that the doctrine of justification by faith alone or Sola Fide would encourage people to live immoral lives and to think that the casual acceptance of Jesus without any change in one’s life is the kind of faith that justifies.

The Protestant Reformers were therefore careful to outline the biblical definition of faith in their writings. They wanted to show that true saving faith would always produce the fruit of good works. Though the reformers believed that works played no part at all in justifying them before God (Rom 3:28; 4:4, 5; Eph. 2:8, 9) they justified or vindicated their claim to faith before a watching world. They believed that their lives should demonstrate that the faith professed was also faith possessed.

The words themselves are simply common Latin words used to describe the elements of faith. Literally translated, they are: 


nōtitia: notice, acquaintance 
assēnsus: agreed with, assented to, approved
fiducia: trust, faith, confidence, credit 


An example of these elements found in scripture:


  13 For this cause also thank we God without ceasing, because, when ye received the word of God (i.e., notitia) which ye heard of us, ye received it not as the word of men (i.e., assensus), but as it is in truth, the word of God, which effectually worketh also in you that believe (i.e., fiducia). (1 Thessalonians 2:13 KJV, emphasis added)


Notitia refered to the content of faith, or those things that they believed. (example: To believe in Christ, you must first know something about him)

Assensus was their conviction that the content of their faith was true. You can know about the Christian faith and yet believe that it is not true. Genuine faith says that the content — the notitia taught by Holy Scripture — is true.

Fiducia referred to personal trust and reliance. Knowing and believing the content of the Christian faith was not enough, for even demons can do that (James 2:19). Faith was only effectual if, knowing about and assenting to the claims of Jesus, one personally trusted in Him alone for salvation. 



 
 Israel, R. (2007). Glasow Road. ISBN-13: 978-1-60034-900-3.
Ligonier Ministries
Reformation Theology,
Sproul, R. C. (2010). Justified by Faith Alone: Wheaton, IL: Crossway Publishers.