Before 1900, Peirce treated abduction as the use of a known rule to explain an observation. For instance: it is a known rule that, if it rains, grass gets wet; so, to explain the fact that the grass on this lawn is wet, one "abduces" that it has rained. Abduction can lead to false conclusions if other rules that might explain the observation are not taken into accounte.g. the grass could be wet from dew. This remains the common use of the term "abduction" in the social sciences and in artificial intelligence.