Logic: Part 5

We could say this is collage logic, but I know of few truly institution of learning that use it most use informal. My point was they are more foundational in nature. Formal logic splits into two fundamentally different types of reasoning: deductive and inductive.

Deductive Reasoning is the logic of proving things for certain. With deductive reasoning, you can begin with a few true statements, and then deduce more statements that you know are also true. You can also analyze arguments to see if they are valid. Deductive reasoning is used is used to validate the truth and certainty to an argument.

1. Classical Deductive Logic - Aristotle, that ancient Greek philosopher guy, was the first to talk about syllogisms. In ancient Greece, men often first presented their arguments in syllogisms, and then they gave their arguments in a more rhetorical form. This form is helpful in understanding key theological principles.

All men are sinners.
Aristotle is a man.
Therefore, Aristotle is a sinner.

2. Modern Symbolic Logic is another method of deductive reasoning. It is a simple and useful method for translating ordinary reasoning into a universal language of symbols. It is good for long complex arguments and is only used by guys with heads so big they have neck problems. Men like Dr Paul! (he he)

Inductive Reasoning is an entirely different form of reasoning from deductive reasoning. Inductive reasoning evaluates the evidence to determine whether an argument is probably true or false. There is less certainty with inductive but it leads itself to arguments like in a science class room.

It is not always possible to prove something for certain. So principles of reason were developed from the evidence in a way that arrives at useful conclusions. One problem with the method is this form of reasoning is subject to a person’s worldview. If your worldview (basic assumptions about life) agrees with the conclusions certainty is assumed wrongly. This is how science theory of evolution can become the corner stone of a scientific worldview. With that said this method is very useful. The benefits of scientific reasoning are in your pocketbook (credit card, cell phones and iPods) or in your living room (TV and computers) even in your bathroom (Acts bath wash [grrr] and medicine). Frances Bacon was a leader in developing this form of reasoning. The Paul the apostle used it in some of his arguments, so Bacon was no baloney.


These are six important forms of inductive reasoning:


1. Analogy builds arguments based on similarities between two things.
2. Generalization reasons from one fact to all similar facts. This is the basis logic for all scientific reasoning. From facts to principle.
3. John Stuart Mill’s Methods for Experimental Inquiry were developed to investigate the causes of scientific phenomena.
4. Hypothetical Scientific Reasoning is used when scientists form theories about the world and test their theories with experiments. The Hard sciences use this method.
5. Statistical Reasoning creates and interprets statistics about our world and draws conclusions from those statistics. Social sciences use this method.
6. Probability is a science closely related to statistical reasoning. It tries to predict the future based on our knowledge of past experiences. Social and political sciences use this method.


Special note – Not one of the six methods of inductive reasoning above can ever prove any idea for certain. They do come in handy sometimes when inventing things like light bulbs and digital cameras, or showing the provinces of social issue.Formal Logic