Little Shop of Knowledge

Chapters 2, 3 and 4 of “The Art of Reasoning” by David Kelley aim at providing the base for clear logical reasoning by clarifying the case of how concepts and propositions are to be constructed.

 

Classification: “The process of putting things together into groups on the basis of similarities”.

 

This chapter talks about the general rules for taxonomy and how to create a functioning organizational framework. Kelley describes concepts such as Genus and Species that serve to “organize the folders” and “files” of knowledge.

 

Rules: (1) A single principle or set of principles should be used consistently so that the categories are mutually exclusive and exhaustive. (2) The principles used should be essential.

 

Definitions: Descriptions that clarify the boundaries of a concept.

 

In this chapter, Kelley breaks apart the many mistakes that people make when defining a concept and the importance of having well built definitions.

 

Main Funtions of a Definition:

1. State criteria for membership in the class of referents.

2. Indicate the relationship between a concept and other concepts.

3. Condense the Knowledge we have about the referents of a concept.

 

Rules for Definitions:

1. Include a genus and a differentia.

2. Not be too broad or too narrow.

3. State the essential attributes of the concept’s referents.

4. Not be circular.

5. Not use negative terms unnecessarily.

6. Not use vague, obscure, or metaphorical language.

 

Propositions: Something we can assert in the form of a statement.In this chapter, Kelley guides us through the nature of what propositions are, how to build them as well as how to recognize the different elements that conform them.

 

Main ideas: (To identify propositions in sentences)

1. Ask what facts are being asserted.

2. Distinguish nonrestrictive clauses, which introduce a distinct proposition, from restrictive clauses, which do not.

 

Comment: 

 

I must say, I really enjoyed the whole process of this book. There is a strange pleasure in seeing things logically. Whether it was classification or definition, these human constructions that go so well with our system have been extremely useful in just about any aspect of my life. Whether learning to spot poorly formed definitions in an article to organizing my computer’s desktop. What I enjoyed the most, I must say, were our dialogues in the garden where we tried to understand and deconstruct an argument in favor of the legalization (and moral apology, I would call it) of abortion. I thought, easy, I already know the counter argument to this. Little did I know that the author opened her claim by disproving exactly my counter argument, which apparently is way more common than I thought. The exercise of analyzing such a delicate subject fascinated me. I think that as a group we managed well, the experience was pleasant and since it was a topic of interest everyone was specially scrupulous in digging for the minutiae in the argument. Whether a poor definition or a mixed classification, most of us were completely immersed in the activity. In the end, though I still hold my previous position (against the legalization of abortion), I have realized that there is still much to learn on the subject. I know have passed from being absolutely sure to a position of not knowing, yet, not one that sounds like giving up, rather one that recognizes our Scientific limitations for the moment and recognizes the need to call for prudence.