7. Causality and Mill’s Methods

 

 

Introduction

Dr. Andrew Wakefield and 12 coauthors argued that because 12 children in a study they conducted had received the MMR vaccination and they also had chronic enterocolitis and regressive developmental disorder, the MMR vaccination must have caused the chronic enterocolitis and regressive developmental disorder. Assuming that correlation implies causation is the false cause fallacy. To better understand how one can make this mistake it is important to understand Mill’s theory of causation.

 

In this lecture I will explain how Charles Meigs and the committed the false cause fallacy by assuming that correlation implies causation in his treatment of Child-Bed-Fever. The correlation between abdominal inflammation and fever is a sufficient condition but it is not is a necessary condition for the fever. We will define Cause - a condition or set of conditions that bring about an effect. We will define precipitating cause - the object or event that bring about an effect until new evidence offers a better explanation. Then we will explain Mill’s Methods and Method of agreement, Method of difference, Joint method of agreement and difference, Method of residues and Method of concomitant variations. I will explain how Oliver Windell Holmes found a cure for Child Bed-Fever by finding a commonality that the women suffering from the illness was most likely the cause. Next I will explain a problems with Mill’s Methods - Mill’s methods can only reveal evidence of probable causes, providing no real explanatory power. Then I will argue that scientists should develop a hypothesis from observed data using abduction, or inference to the best explanation, thus going with the inference is the most probable. Finally I will end by defining the Post hoc Fallacy.

 

 

 

Meigs and the committed the false cause fallacy by assuming that correlation implies causation

In his search for the cause of Child-Bed-Fever Charles Miegs concluded that because abdominal inflammation, in women who have recently went through child birth, occurs before a fever, the inflammation must have caused the fever! This is incorrect. Meigs committed the false cause fallacy by assuming that correlation implies causation. Simply because two things occur at the same time does not mean that one causes the other. This like saying that just because your teeth come in before you hit puberty, tooth growth causes puberty.  

 

 

 

 

The correlation between abdominal inflammation and fever is a sufficient condition but it is not is a necessary condition for the fever

What we have here, with this correlation between abdominal inflammation and fever is a sufficient condition – this occurs whenever one event guarantees that another event occurs. Scientific reasoning proceeds on the assumption that there are discernable causal relations between objects and events. Understanding causality requires a grasp of the concepts of sufficient and necessary conditions. Besides sufficient conditions there are necessary conditions. A necessary condition means that one thing is essential, mandatory, or required in order for another thing to be realized. 

It is not clear whether abdominal inflammation is a necessary condition for the fever.  

The relationship could simply be coincidental or the fever could cause the abdominal inflammation.  

 

 

 

 

 

 

Cause - a condition or set of conditions that bring about an effect

Either way it is possible that there is a cause for both events. A cause can be defined as a condition or set of conditions that bring about an effect. When we talk about a set of conditions, we are talking about a causal network. Establishing the normal state of a system helps in defining the abnormal state of a system, or any change from the normal state requires an explanation, typically a causal one.  

The normal state, in this case is a state of not having a fever or abdominal inflammation. The abnormal state is having fever and abdominal inflammation. 

 

 

 

 

Precipitating cause - the object or event that brings about an effect until new evidence offers a better explanation

Going forward we will assume that there is a precipitating cause - the object or event directly involved in bringing about an effect- until evidences takes us to a better explanation. A remote cause is something that is connected to the precipitating cause by a chain of events. 

 

 

 

 

Mill and Method of agreement, Method of difference, Joint method of agreement and difference, Method of residues and Method of concomitant variations.

As Mill has already discovered accurately determining causes and effects is difficult. We can often confuse the two, or misidentify one because we lack sufficient information. Mill’s methods are attempts to isolate a cause from a complex event sequence. 

1.                Method of agreement: Two or more instances of an event (effect) are compared to see what they have in common. That commonality is identified as the cause. 

2.                Method of difference: Two or more instances of an event (effect) are compared to see what they all do not have in common. If they have all but one thing in common, that one thing is identified as the cause. 

3.                Joint method of agreement and difference: A combination of the methods of agreement and difference, the joint method looks for a single commonality among two or more instances of an event, and the joint method looks for a common absence of that possible cause. 

4.                Method of residues: all known causes of a complex set of events are subtracted. What is leftover is said to be the cause. 

5.                Method of concomitant variations: correlations between varying events are sought, that is, correspondence in variations between two sets of objects, events, or data. 

 

 

 

 

Oliver Windell Holmes found a cure for Child Bed-Fever by finding a commonality that the women suffering from the illness was most likely the cause

Let’s move from Meigs to Oliver Windell Holmes. Using this method of finding a commonality between patients who suffered from child-bed fever he determined that doctors who performed births are doing autopsies on women who suffered child-bed-fever where the main thing shared between women suffering child bed fever. We can see the method of agreement: Two or more instances of child bed fever were compared to see what they have in common, the doctor. That commonality is identified as the cause. We also see method of concomitant variations - correlations between varying child bed fever victims were sought. In these cases the doctor didn’t wash his hands, so an invisible contagion could infect people. 

 

 

 

 

Problems with Mill’s Methods - Mill’s methods can only reveal evidence of probable causes, providing no real explanatory power.

There were some limitations of Mill’s Methods. Mill’s methods can only reveal evidence of probable causes; they provide no real explanatory power. Discovering instances of causation is an important step in understanding the world—but it is only part of what we need. We also need to understand how and why particular instances of causation function as they do. Answers to these questions take us beyond being able to identify cause-effect relationships. We must develop theories and hypotheses—the basis of scientific reasoning. 

 

 

 

 

Scientists should develop a hypothesis from observed data using abduction, or inference to the best explanation, thus going with the inference is the most probable. 

Scientists, like the late Oliver Windell Holmes, proceed by developing a hypothesis from observed data. A hypothesis is a provisional and testable explanation for facts. Theoretical scientists propose hypotheses to explain natural phenomena, while experimental scientists conduct tests of those hypotheses. 

The process whereby a hypothesis is developed is called abduction. Inference from facts to an explanation of those facts, particularly where patterns occur, is an abductive inference. 

To resolve conflicting inferences for the same facts, we often have recourse to inference to the best explanation, which is to say, when the inference is the most probable. 

 

 

 

Post hoc Fallacy 

This states that "Since event Y followed event X, event Y must have been caused by event X."  

This fallacy occurs when two events happen either at the same time or the chronological ordering is not important or not known. According to this fallacy correlation seems to imply causality. This fallacy occurs when a conclusion based only on the order of events, and not considering other factors that could be responsible for the result. These factors could destroy the connection. 

A simple example is ‘my uncle farts immediately before sunrise; therefore his farts cause the sun to rise.’ 

·                     A occurred, then B occurred. 

·                     Therefore, A caused B. 

I ate chili before the Cardinals game and they won. My eating chili caused the Cardinals to win. 

Some people were diagnosed with illnesses shortly after receiving vaccinations, the vaccination caused the illness.  

 

Charles Meigs not only committed the false cause fallacy - assuming that correlation implies causation- but Charles Meigs and Dr. Andrew Wakefield also committed the Post hoc Fallacy. They assumed that just because one event followed another. The first event must have caused the second event.

 

 

 

Conclusion
It should be clear now as to how Charles Meigs committed the false cause fallacy by assuming that correlation implies causation in his treatment of Child-Bed-Fever. The abdominal pain was not the cause. As Oliver Windell Holmes found, the cause was dirty doctors not washing their hands. While it is important to understand Mill’s methods they can only reveal evidence of probable causes, providing no real explanatory power. While Charles Meigs and Dr. Andrew Wakefield both committed the false cause. They both also committed the Post hoc Fallacy.