H. Epistemological issues
1. Scientific laws
Scientific laws are descriptive generalizations having predictive value. An example would be Newton's law of gravitation:
Every particle in the universe attracts every other particle with a force directly proportional to the product of the two masses and inversely as the square of the distance between them.

Unlike theories, laws are discovered, rather than devised. Their truth is highly probable. That is, the mathematical likelihood of events ocurring according to them are very high.
They are universal hypotheses which are capable of being confirmed or disconfirmed by empirical findings.
2. Hypotheses
Hypotheses are particular, explanitory statements; they are educated guesses. George is dead on the floor. Why? Maybe he drank poison.
3. Theories
Theories are general explanatory statements or explanitory models. Hypotheses and theories are 1) provisional yet probable because they are grounded in facts; and 2) they are predictive because they are capable of accounting for the facts.
In establishing a particular hypothesis or general theory, induction leads to the generalization that is the theory proposed or suggests the hypothesis that is proposed. Deduction on the other hand, determines whether the generalization or theory implies the facts serving as evidence. Confirming the facts makes the hypothesis or theory probable.
4. Causality
Causal principle has at least three general interpretations:
a) Empirical (a posteriori) interpretation. Cause is a generalization from the facts and dependent on the facts. Cause is the observed constant conjunction of certain events. Whenever A, then B.
b) Rational (a priori) interpretation. Cause is viewed as a necessary connection between two events, wherein an appropriate effect must follow the cause according to the principle of sufficient reason. We know a priori that causality is a necessary principle of reality, that there can be no uncaused evnents, or that causality is a necessary principle of knowledge. If A, then B.
c) Pragmatic interpretation. Cause is viewed as a useful or guiding principle of scientific explanation, althought much of science may not need it. One version is the "recipe" theory, wherein cause is likened to a recipe for producing or preventing something. We produce B by producing A and speak of A as causing B. That is, we cause iron to glow by heating it and therefore speak of the heating of the iron as the cause of its glow. Another version pictures the causal principle as a proposal to uncover uniformities in the world -- that is, a procedural rule which is neither ture nor false because it is not about anything but is merely a fruitful way of looking at or dealing with anything.
Some considerations of causality:
1. Causality is not the same as logical necessity -- as in "Black cats are black."
2. Causality in science is not prescriptive, as in "The law commands obedience".
3. Causality as a necessary condition (if effect, then cause) does not mean necessary connection. Necessary condition means that in the absence of a particular condition, a particular effect never occurs -- as in "In the absence of oxygen, we never have fire."
4. Causality as a sufficient condition (if cause, then effect) also does not mean necessary connection. Sufficient condition means that a particualr condition is always followed by a certain effect, as in "If rain is falling, the ground is wet." Cause as necessary or sufficient condition is empiricist theory. Cause as necessary connection is traditional rationalist theory.
5. Cause is usually taken to mean the whole set of conditions sufficient for the occurance of the event. If the cause is singular, these sufficient conditions are also necessary conditions. If the cause is plural, these sufficient condititions are not all necessary conditions.
5. Scientific explanation
"Why is an ambiguous question -- it may be a request for either a reason or an explanation.
Reasons are given for holding beliefs -- as in giving reasons for why one believes the world is round.
Explanations are given for what occurs -- as in explaining why earthquakes happen or why carbon monoxide is poisoness. These are scientific explanations, although "explain" can be used in other ways, as in refering to making an idea clear.
One may have reasons for believing certain things, and these reasons may also be explanations for believing them, as in when one wants to believe what is true. On the other hand, one may give reasons why, that is, he believes that God exists or that a certain kind of act is wrong. One may justify his beliefs. This is a logical matter; whereas the explanation of his beliefs about God or morality, that is, the psychological question, is something else. He may, for instance, have had certain experiences or needs that caused the belief. These would explain the belief. Explanations have to do with causes.
Scientific explanations are scientific laws, hypotheses, or theories. The laws, hypotheses or theories are the explanation. An event is explained when it is "brought under" a law, hypothesis, or theory.
The covering law model of scientific explanation is as follows:
All copper conducts electricity (explanation)
This substance is copper.
This substance conducts electricity (thing to be explained)
The statement about what is explained is deduced from the explanation, i.e., all the premises together, of which at least one is a generalization -- a scientific law, hypothesis, or theory. If the part of the explanation is only probably true, the explanation is probable. The generalization need not be empirical. It may be logical, as in: "One person can't be at two places at the same time." In this case the explanation is logical rather than empirical or scientific.
A scientific explanation must have predictive value; that is, it must be able to explain events other than the one it is invoked to explain and therefore be able to predict the occurence of these events.