Philosophic Theory Evaluation

In this paper, a theory will be evaluated. First of all, I will start by introducing the case, which is that scientists studied twenty terminal cancer patients and found that they have different length of lives after being diagnosed. So the problem that needs to be explained is: “What is the factor that causes the difference in cancer patients’ life span?” The possible explanation given here is “a positive attitude can lengthen cancer patients’ lives” and this is the theory we want to assess.

I will start examining the internal and external consistency of this given theory. Obviously, it is internally consistent because there is no contradiction in the theory itself. It clearly states that a positive mood can lead to a longer life. The theory is also external consistent because it accounts for the phenomenon that it need to explain. Here we are investigating the cause of difference in length of life and the theory is a fairly possible explanation. Then, I want to continue by accessing the evidence for this theory. In this case, scientists can prove that patients with positive attitudes live longer than those with negative attitudes because they have actually taken note of the mental attitudes and corresponding life span of the patients. One problem might be that it is difficult to judge patients’ moods because they may vary from time to time and there is no clear line between happy and sad, calm and angry. So it is not easy to say for certain that a patient is positively or negatively orientated. The most important criteria that we need to consider is the criteria of adequacy, which includes testability, fruitfulness, scope, simplicity and conservative. First of all, this theory is testable because “it can predict something other than what it was introduced to explain” (p319, Lewis Vaughn, 2005). If scientists take another two hundred patients and record their mental attitudes, we can see that if the results still follow the theory. Secondly, according to the textbook, a theory is fruitful if it can successfully predict previously unknown phenomena. In this case, the theory is not fruitful because it is not predicting something that no one expects to happen. Thirdly, scope refers to the diversity of phenomena that a theory can explain. In this case, the theory has a very small scope because this is the only scenario it can explain, which is the relationship between people’s mood and life span. In addition, the degree of simplicity refers to the number of assumptions that the theory make. This theory is very simple since it almost does not make any big assumption. The only probable assumption here is that it says “cancer patient” and as we know, this theory may be applied to all the human beings. Lastly, conservative theory means that it fits with our established beliefs. In this case, the theory is obviously conservative because we all know that, others being equal, a happy mood