INFERENCE

Inference – it is a process by which the mind proceeds from one proposition to another proposition seen to be implied in the former. It is the fundamental element in an argument. Without inference, there can never be an argument.

Example:

                Givens                                                                                                  Therefore:

The cloud is dark.                                                             It will rain.

All people have dignity.                                                 That poor man has dignity.

“All people are mortals” is true.                                 “Some people are not mortals” is false.

Some politicians are corrupt.                                      Some corrupt people are politicians.

Two Kinds of Inference

1.       Mediate Inference – an inference which requires a mediating proposition.

Example:

(a)    All people are mortals.

(b)   Socrates is a person.

(c)    Therefore, Socrates is mortal.

It is a mediate inference because we cannot arrive from (a) to (c) without going through (b).

Other example:

(a)    Some students are rich.

(b)   She is a student.

(c)    Therefore, she might be rich.

2.       Immediate Inference – a kind of inference which does not require a mediating proposition.

Example:

(a)    No people are immortals.

(b)   Therefore, all people are mortals.

(a)    All objects occupy space and have mass.

(b)   Therefore, there are no objects that do not occupy space and have no mass.

There is no need for a mediating proposition here. You proceed from (a) to (b) without going through any proposition.

Caution: There are inferences which seem to be an immediate inference but will be found to be mediate inferences upon careful analysis.

Example:

(a)    The cloud is dark.

(b)   Therefore, it will rain.

It seems that there is no need for us to go through a mediating proposition to arrive at proposition (b). However, if we analyze it carefully we will discover that proposition (a) is not enough in order for us to arrive at proposition (b). This entails that there is a hidden proposition which mediates (a) and (b). That mediating proposition is: “Whenever the cloud is dark, it will rain.”

Other examples:

(a)    Today is February 14.

(b)   Therefore, it is Valentine’s Day.

(a)    Students must be diligent in their students.

(b)   Therefore, you must be diligent.