With Anthony Weston’s fifth chapter of A Rulebook for Arguments, we are immediately introduced into an example of arguments about causes, what the chapter is about.
In his eighteenth point, causal arguments start with correlations, the author states the significance of examples when talking about arguments about causes — having correlations. Weston says, “The evidence for a claim about causes is usually a correlation — a regular association — between two events or kinds of events: between your grades in a class where you sit in the classroom; between being married and happy; between the unemployment rate and crime rate, etc.”  Essentially, Weston is emphasizing the importance of the examples in causal arguments having relations. When talking about causal arguments, you cannot talk about two topics that have absolutely nothing in common or correlation: the rate of texting and driving and how many babies are born in the U.S. Here is an example of causal arguments included by Weston, which is crucial to understand to firmly grasp this chapter’s main idea:
“Event or condition E*1 is regularly associated with event or condition E*2.
Therefore, event or condition E*1 causes event or condition E*2.” 
Lastly, there are inverse correlations in which an increase in one factor leads to a decrease in another factor.
Although causal arguments with correlation are often more “compelling” and common, correlations may have alternative explanations. The primary point is that any correlation can be interpreted or explained in many ways. Just because there are coincidences does not mean it is premise for causal connection. However, even when there is a causal connection, it is important to note that it “by itself does not establish the direction of the connection.”  Additionally, Weston mentions that there can be other outside sources affecting the reason something things correlate.
In Weston’s next point, he emphasizes the importance of working towards the most likely explanation. Essentially you want to be able to conclude reasonable outcomes and not ones that do not correlate — or make sense. It’s usually in conspiracy theories that people spend focused on things that are not getting them closer to what is probably true, but instead, deviating them farther away from the truth. Which is why conspiracy theories are sometimes hard to believe, for example, the JFK assassination having any kind of connection with 9/11. It’s important to understand the logical side of what you want to correlate.
In the twenty-first point of the book, the author wants the audience to note that in causal arguments to expect complexity. Sometimes causal arguments are not basis for all things true and instead are just basis for some arguments. For example, people who are married are generally happy. This does not mean that when someone gets married they immediately achieve happiness, but rather, it is a generalization and not de facto. Therefore, causal arguments can become complex in trying to explain why perhaps one thing causes another, but not entirely or absolutely. Something important Weston mentions is: “Causes and effects may interpenetrate as well. Reading, instance, surely does lead to open-mindedness. But open-mindedness also leads to reading ... which creates more open-mindedness in turn.”  This is important to note because, as stated previously, it is important to take into consideration the causes and effects, and that correlations are no de facto, but are very complex.