1. Chapter 13 Science and Hypothesis

2.  Modern science has had a profound impact on our lives— mostly for the better.  The laws and principles of science are valuable quite apart from their practical usefulness, though.  They are also important in that they satisfy our curiosity about the world.  We can, to be sure, know particular phenomena merely by observation.  Science seeks not only to record these things, but also to understand and explain the general laws that govern all such phenomena Chapter 13

3.  Explanations (scientific and otherwise) are stories or statements from which a thing to be explained can be logically inferred, and whose acceptance removes or diminishes its problematic or puzzling character.  Explanation is really the same thing as inference regarded from a different point of view.  The chief criterion for judging explanations is relevance, though it is not, by itself, sufficient.  One might expect that explanations must also be true as well—but even most scientific explanations cannot be directly verified as true or false. Chapter 13

4.  Even though myths and scientific explanations share the lack of direct verification, they are different in important and crucial ways.  Science and dogma take different attitudes towards explanations:  Dogmatic explanations are regarded by those who hold them as  absolutely true and beyond correction.  Scientists, on the other hand, take scientific explanations as tentative, merely as hypotheses.  Furthermore, there are reasons for holding scientific beliefs— usually sensible, empirical evidence; unscientific explanations have no rational basis for accepting or rejecting them. Chapter 13

5.  In addition, there are seven stages of any genuinely scientific investigation:  1. Identification of the problem  2. Construction of preliminary hypotheses  3. Collection of additional data  4. Formulation of the hypothesis  5. Deduction  6. Testing of the consequences deduced  7. Application of the theory developed Chapter 13 – 7 stages

6. 1. Identifying the ProblemEven a genius needs a problem. 2. Devising Preliminary Hypotheses Required to decide what evidence to collect. 3. Collecting Additional FactsThe heart of the work. 4. Formulating the Explanatory Hypothesis Requires imagination to see the point. 5. Deducing Further Consequences Will point to new facts and hypotheses. 6. Testing the Consequences Attempts (hopefully unsuccessful) to disprove the hypothesis. 7. Applying the Theory Knowledge requires application (to be useful). 7 Stages Chart - Example

7.  There are three criteria by which scientific hypothesis are evaluated:  1) Compatibility with previously well established hypotheses or explanatory hypotheses  2) Predictive power or explanatory power – hypotheses must be testable, and requires observable fact(s) that can be deduced from the tests  3) Simplicity of competing theories Chapter 13 - Criteria

8.  Crucial experiments allow the testing of two competing hypotheses to determine which is correct.  They are sometimes difficult or impossible to set up; furthermore, since it is impossible to test only one hypothesis at once, we cannot always be sure which theory is in error.  Some scientists, when a hypothesis is under attack, seek to save it using an ad hoc hypothesis.  Such hypotheses, which are undertaken only to save other hypotheses and have no other predictive or explanatory power, are generally regarded with scorn. Chapter 13

9.  Classification, though it is often seen as merely the first undeveloped stage of a scientific field, actually remains a valuable instrument of scientific inquiry.  This is because classification suggests general truths and helps to formulate powerful explanatory hypotheses.  Closely akin to description, classification has both practical and theoretical motives.  Even historians, because they can never describe any event in complete detail, rely on the selective recording of details—and it is classification that serves as the basis of the decision, regarding what is relevant and what is not. Chapter 13

10.  Questions for Discussion  1. Has science been, on balance, a benefit to mankind? Are our lives better, freer from pain and disease, more valuable and pleasant, more meaningful? Consider the whole history of science (as far as you know it) to evaluate this question.  2. What is the difference between a theory, a hypothesis, and a law? How is this difference important to the distinction between science and dogma?  3. Why is relevance not a sufficient condition for judging a scientific hypothesis valid?  4. What are the five criteria by which scientific hypotheses are evaluated? What are the requirements of each?  5. Why is each of the seven stages of scientific investigation necessary? Why couldn’t a few of the steps be dropped? Chapter 13