Rufus says: "In the first part [Aristotle] intends this argument: In every natural thing there is something [that serves] as matter, something as agent, and something as effect in matter; therefore since the soul is something natural insofar as we intend to treat it here, something [that serves] as matter, something as agent, and something as an effect in matter [produced] by the agent is found in the soul; therefore there is an agent intellect. "

Original Latin

The Origins of Psychology: Not on a Couch!
This is an excerpt from one of the Western world’s earliest psychology lectures.  Psychology was first taught by explaining and then asking questions about what Aristotle had said about the soul or psyche. Psyche is the Greek word for soul from which we get the word "psychology".

Psychology is the name for the study of human sensation, perception, thought, will, attachment, and emotion.  As it was first taught, psychology did not discuss neuroses, personality or personality disorders.  Nonetheless, it was a deeply controversial topic, and some theories about the composition of the human soul were regarded as heretical by the Roman Catholic Church.

A Fourfold Intellect
This particular lecture is about the basic composition of the human intellect. Richard Rufus is discussing the passage in Aristotle where Aristotle claims that the human intellect (like everything else) combines an active and a passive aspect.  Aristotle and Rufus, following him, both conclude that there are three basic elements in the intellect:

1. the active agent intellect
   
2. the possible intellect that serves as the passive matter on which the agent acts -- the subject that thinks -- and 
   
3. the effect of the agent’s action on the possible intellect, often called the acquired intellect or the intellectus adeptus -- what we would call a "thought."
   

In this chapter Rufus lists a fourth aspect of intellect – namely, imagination. In medieval psychology, imagination presents sensory perceptions to the intellect.  The intellect then abstracts thoughts from sensations.

Suppose you see a tree. Your imagination offers the intellect an image of that tree.  The agent intellect abstracts the concept of "tree" and shapes the possible intellect accordingly.  As a result you can form the thought -- or acquired intellect -- that all trees are woody.

Outline, Exposition, and Question
For Rufus this section of Aristotle's De anima was from book 3, and these discussions were chapter 4 (in modern editions, they are chapter 3).  Rufus starts his lecture by outlining the chapter and then explaining what it says --  that's the "exposition" -- and finally asking questions about it.  We number the sections in his lectures according to this structure.

• 4.D1 stands for chapter 4, the first outline section
• 4.E1 is chapter 4, the first section of exposition
• 4.Q1 is the first question of chapter 4

In this excerpt, Rufus asks four questions:

• 4.Q1 Is the possible intellect in some sense actual?
• 4.Q2 Are the agent and the possible intellect really the same?
• 4.Q3 Do children have a possible intellect, and if they do, what purpose does it serve?

The most deeply controversial of these questions was the second.  Important authorities such as Ibn Sina (Avicenna) held that the agent intellect was divine.  But if that is the case, then the human possible intellect was certainly not the same as the agent intellect. 

A Split Intellect?
Among Rufus’ Christian contemporaries the most pressing question was whether the agent and possible intellects were the same substance or distinct substances.  Authors who held that they were the same substance claimed that

• the agent intellect was the intellect considered in itself, and
  
• the possible intellect was the intellect considered according to its inclination to receive intelligible ideas. 

Because this position relies in part on Augustine’s claims for the unity of the human soul, people sometimes called it the theological position.

Rufus wrestles with this question before deciding favor of what was often called the philosophical position.  In this early work, Rufus held that the agent and possible intellects cannot just be different aspects, acts, or beings of the same substance, since they are so different – they come into and go out of existence at different times, and they seem to have contradictory properties.   Putting it precisely:

• The agent intellect is created before the body, while the possible intellect exists to link body and bodily imaginations with the intellect.
  
• When created the agent intellect has all intelligible ideas, while the possible intellect has no ideas before it receives images from the imagination.

Rufus explains his ideas by interpreting one of the controlling metaphors  used to explain thought: light shining on color to make it  perceptible. 

• The agent intellect with all its innate ideas is like light which is comprised of all the colors -- think of how white light looks when it is split by a prism. 
  
• The possible intellect is like the air or the medium through which we see colors; it is the medium in which ideas or species are received. 
  
• The acquired intellect is like the colors we see.

Notice that Rufus does not just bluntly state the philosophical position: there must be more than one substance here.  He confines himself to the negative conclusion that agent and possible intellect cannot be entirely the same.  This reflects the fact that explaining how things could be in some sense the same and in another sense different was one of Rufus’ major philosophical concerns. 

Eventually, he dealt with some of the thorniest of these problems by developing a theory of  formal predication, according to which two things could be really the same and yet formally distinct if their definitions were different.  Quite how this solves the problem is not clear, since it seems that things that come into and go out of existence at different times are really not just formally distinct.  But that is a problem for another day.  What is clear in this passage, however, is that Rufus was still struggling with the problem.

Do children have an intellect?
By contrast to this deeply troubling problem, Rufus finds it easy to deal with the last question: Do children have intellects before they begin to reason?  He says that children can have the potential for thought before they exercise their intellects.  And even before they start to think in abstract generalities, the presence of the agent intellect serves a purpose by ennobling and illuminating their imaginations.  So the passage ends on a light note – pun intended!