Discussion Question Number Three: Part Six

Checking for Validity with Diagrams

Chapter eight of Epstein introduces a great concept concerning the discovery of an argument's validity. The textbook provides many points in proving or disproving the validity. Page 164 of the Epstein illustrates the concept bullet by bullet, ultimately conveying six important points in understanding and creating this diagram. (1) The first defines the representation of a particular area that is enclosed, called a collection. (2) The second clarifies the idea that if one area is inside another area completely, then all that is inside that one area will also be in the other. (3) The third describes if a part of an area goes over inside another, then there will be a shared portion, meaning there's a commonality, among the two. (4) The fourth is the exclamation that if two areas do not happen to go over one another, then there will be no connection of either one to the other. (5) The fifth establishes a point in an area, shown as an "a" or dot, that demonstrates that a certain object belongs in that collection. (6) The sixth lastly explains the ability of being able to draw places or areas in that "represent the premises as true while trying to represent the conclusion as false," (164) and what it means if it is successful (the argument is invalid) and vice versa (the argument is valid).