Perhaps it is better to look at Mill`s methods more modestly than the tools we can use in our efforts to confirm hypotheses about the natural world. If we have already made several specific assumptions about what might be the cause of an observed event, then the use of the methods will be useful, as it often allows us to eliminate most of the possible causes that we have identified, which tends to confirm the hypothesis that any remaining circumstance is likely to be the true cause. “Method of agreement.” dictionary Merriam-Webster.com, Merriam-Webster, www.merriam-webster.com/dictionary/method%20of%20agreement. Retrieved 30 November 2020. This situation is an example of Mill`s common method of agreement and difference: the first four students are proof that all those who got sick had eaten coleslaw, and the corresponding four couples are proof that only those who got sick had eaten coleslaw. This is a powerful combination of the first two methods, as it tends to support our idea that real causes are necessary and conditions sufficient for their effects. To see how each of the five methods works, let`s look at their practical application to a particular situation. Suppose that on an otherwise uneventful afternoon, the college nurse realizes that an unusually high number of students are suffering from severe indigestion. Ms. Hayes, of course, suspects that this symptom is due to something the students ate for lunch, and she wants to know for sure. The nurse wants to find evidence to support the conclusion that “eating `xxxx` causes indigestion.” Mill`s Methods can help. If our main goal in applying Mill`s methods was to discover the unknown cause of an observed event, then they would let us down exactly when we need it most.
The methods show us how to identify the probable cause from the possibilities we have considered in the relevant precursor circumstances of this effect. But the most interesting cases will be those where the cause we are looking for is in an unexpected source that we have probably excluded from our analysis of the previous circumstances as irrelevant. Therefore, Mill`s methods cannot help us discover causes unless we already know (approximately) what those causes are likely to be. One of the main features of scientific methodology is verification and falsification. Let us remember From Cap. 4 that a call to ignorance is made when we conclude from a lack of evidence that something is or is not the case. While there are times when a lack of evidence should lead to a verdict that the original claim is unsubstantiated (as in a criminal court), this is not the case in scientific practice. But what is sufficient evidence of causality? Although we typically use conditional statements to express our causal beliefs, the logical connection known as material implication seems to capture only part of what we have in mind.
Even considering cause as a necessary and sufficient condition for effect does not cover our entire concept of causality. There may be fewer here than you may see at first glance; David Hume pointed out that our causal beliefs are unjustifiable, even if they come naturally. What prompted you to look for the method of agreement? Please let us know where you read or heard it (including the quote if possible). This scheme of reasoning illustrates Mill`s method of residues: it is shown that many elements of a complex effect result from multiple elements of a complex cause through reliable causal beliefs; All that remains of the effect must then have been created by what remains of the cause. Notice that when we accept the truth of all the causal relationships involved, this method becomes an application of deductive reasoning. This principle, also called simply “common method”, simply represents the application of the methods of agreement and difference. Mill`s methods can only reveal clues to probable causes; they offer no real explanatory power. Discovering cases of causality is an important step towards understanding the world, but it is only part of what we need. We also need to understand how and why some cases of causality work the way they do. The answers to these questions take us beyond the ability to identify cause-and-effect relationships. We need to develop theories and hypotheses that underpin scientific thought.
This method is also commonly known as the most similar system design in comparative politics. Symbolically, the common method of agreement and difference can be represented as follows: As an example of the method of difference, consider two similar countries. Country A has a center-right government, a unified system and was a former colony. Country B has a center-right government, a unified system, but has never been a colony. The difference between countries is that country A willingly supports anti-colonial initiatives, while country B does not. The difference method would identify the independent variable as the status of each country as a former colony or not, with the dependent variable supporting anti-colonial initiatives. It is because of the two similar countries, the difference between the two is whether or not they were a colony. This then explains the difference between the values of the dependent variables, with the former colony supporting decolonization rather than the country without the history of the colony. Knowledge is expanded when we can verify or falsify a hypothesis. This is because experimental tests are designed in such a way that the hypothesis is likely to be a widely applicable explanation of certain facts and not an isolated case.
This type of experiment is controlled, which means that experimental configurations differ by only one variable (see Mills` Difference Method). .
