Inference – What is it, concept, methods, validity and examples

We explain what an inference is, what are the methods to obtain them and various examples. Also, in which cases are they valid.

Inference allows conclusions to be drawn from certain premises.

What is an inference?

In logic, inference is called the process by which certain conclusions are obtained from a specific set of premises. That is, when a conclusion logically derives from what is stated in its premises, it is said that it is inferred from those.

The word “inference” comes from Latin, and is made up of the prefix -in (“Towards”) and the verb ferre (“Lead” or “lead to”), so that it can be understood as the logical process that leads from a premise to a conclusion, or also, that it tries to discover the logical meaning between the premises and the conclusions, that is, to find a implicature.

In fact, inferences are the primary object of study of logic, which classifies and organizes them according to the type of reasoning used to obtain them, as follows:

  • Inferences obtained by deduction, that is, by the use of valid arguments that allow to extract the implicit meaning in the premises.
  • Inferences obtained by induction, a process opposite to the previous one, in which a general, universal conclusion is sought, based on singular premises.
  • Inferences obtained by probability, which consists of finding more or less possible conclusions from the frequency with which the premises are manifested.
  • The inferences obtained through statistical reasoning, that from a known percentage of elements, concludes the possibility that certain conditions are satisfied.

The validity of an inference does not lie in the truth or falsity of its premises, but in the validity of the reasoning that connects premises and conclusions. Thus, it is possible to obtain true or false conclusions through a valid inference procedure. For example, it is possible to infer that if all men are mortal, and Mary being a woman is not a man, then Mary can be immortal.

Examples of inferences

The following reasons are examples of inferences:

  • All known planets are round and Earth is a planet, so Earth is surely round.
  • If it dawns every day, it is certain that tomorrow it will dawn again.
  • If out of a population of 100 people 70 do not eat meat, it is possible to affirm that the majority of the population is vegetarian.
  • If all things eventually fall, when you throw a stone, it will eventually fall.