The Use of Inductive Reasoning in Science

Reasoning that draws a general conclusion based on a set of examples is called Inductive reasoning.

Basic pattern of Inductive Reasoning

a, b, c, d, e, f, g and h are part of group A.

a, b, c, d, e, f, g and h have property G.

All member of group A have property G.

When in Science it starts with observations looking for the patterns to develop a hypothesis as general description of the observations.

With inductive reasoning general conclusions can be drawn from specific observations and the evidence allowing conclusions based on patterns in that observations and evidence. Having too small of a sample size for a general conclusion is a major risk of inductive reasoning. As a result it can easily be affected by philosophical assumptions and biases. This can occur in the selection of the sample and in the patterns recognized, as well as the conclusions drawn from those patterns. Knowing about these problems helps one avoid them.

The Use of Deductive Reasoning in Science

The act of  reasoning that starts with a given set premises and draws a conclusion is called deductive reasoning.

Deductive reasoning begins with general concepts and principles and draws specific conclusion by starting with a given set premises and draws conclusions from them. The conclusions made by way of deductive reasoning are only as valid as the premises on which they are based such that only one false premise can produce a false conclusion. A valid deductive argument t is one where its truth necessarily follows from the starting premises. A sound deductive argument is one that is valid and all of its premises are true other wise it is considered unsound.

A common form of deductive reasoning is called a syllogism It has three parts.  The first part is a set of general characteristics belonging to a category of objects. The second shows that the object under discussion belongs to that category The conclusion that the object under discussion has that general characteristic.

Deductive reasoning dependents entirely on the validity of premises being used. The premises used may be facts derived from observation or a totally philosophical assumption.

Deductive reasoning is a very useful tool of reasoning however it does have its difficulties. It depends heavily on the accuracy its starting premises. However flawed premises result in flawed conclusions. These difficulties need to be properly understood to properly understand scientific statements including those of both Creationists and Evolutionists.

A Description of Logical Fallacies

A Logical Fallacy is an error within a logical argument that is a flaw in the argument’s structure that is said to invalidate the argument. A logical fallacy is independent of the truth so a fallacy does not necessarily invalidate the argument's premises and conclusions. However arguments derived from logical fallacies often do lead to an incorrect conclusion due to faulty reasoning.

Examples

Ad hominem
Latin: “To the Man”
It is an argument that attacks people holding a particular point of view rather than attacking the point of view itself. A good example is the case where an opponent starts insulting you in some manner rather than countering your argument.

Overgeneralization
It is an argument which makes a statement so broad as to exceed the original point that was trying to be proved. Often it involves taking a small sample and generalizing it to the whole group.

Non sequitur
Latin: "It does not follow"
It is an argument which moves from a premise to a conclusion where no connection exists between the two.

Proof by authority
It is an argument which is based on a person's authority, rather than on the merits of the authority's position. A good example is a argument is assumed correct because it comes from a person with a PHD.

Proof by assertion

It is an argument which simply states something as true without evidence or argument to support it.

Circular reasoning
It is an argument that tries to prove something by first asserting it and then trying to "prove" it.

Straw man
It is an argument where a person argues against a position similar to but weaker than their opponent’s real position.

Manufacturing facts from a theory

It is an undemonstrated or unobserved idea that is stated as fact because it agrees with a particular theory.

Your theory does not work under my theory, so your theory must be wrong
It is a form of circular reasoning where the person tries to disprove a point of view by interpreting the facts through a different point of view.

There are many more logical fallacies avoid them.

A Discussion of Logic and Reason in Science

The set of principles and rules for reasoning is called logic. If used correctly beginning with the right starting point one will arrive at the correct conclusion.

Reasoning that starts with a given set premises and draws a conclusion is called deductive reasoning. Reasoning that draws a general conclusion based on a set of examples is called inductive reasoning. So deductive reasoning goes from general principles to specific conclusions and inductive reasoning goes from specific principles to general conclusions. Both of these types of logic are used in science.

Inductive and Deductive reasoning are different and even opposite concepts but in practice deductive and inductive reasoning are often used together even without knowing it.  For example one may be drawing a general conclusion form observed evidence (induction) based on general principles called assumptions. (deduction)

Mistakes in reasoning called Logical fallacies are some times made. This can happen both deliberately and accidentally. The important thing is to avoid them since they resultant in erroneous conclusions.