Terminology Tuesday: Inference

Inference: In everyday usage, when people speak of an inference they sometimes mean a ‘guess’ based on the information they have, or the conclusion they have reached – again, based on other things they believe. For example, after reviewing the evidence a detective might say, ‘The inference is that we should question Jones again about this case.’ In our context, the usage is derived from logic, where it means the ‘step’ from reasons to conclusion, the ‘move’ from one to the other. Thus, if someone argues, ‘Some people have solved their own unemployment problem by great ingenuity in searching for a job or by willingness to work for less so all the unemployed could do this’, the inference is the move from ‘some people have…’ to ‘all the unemployed could do this’. Though the reason presented in this argument has often been true, the inference to the argument’s conclusion is much more questionable.1

1. Alec Fisher, Critical Thinking: An Introduction (Cambridge: Cambridge University Press, 2001), p. 240.