[…] instead of identifying an utterance as an ordered set (a particular permutation) of particular morphemic segments, we would identify it as a set (a combination) of particular morphemic elements. If the segments in question have contrasting arrangements, one of these elements will consist not of adding some phonemes to the utterance, but of adding arrangement among the sets of phonemes. In that case, we may say that the arrangement is morphemic […]. I.e. not automatic for the morphemic segments in the utterance. In the same sense, we call any phonological segment or element phonemic if it is not automatic in respect to the other phonological segmentations and elements of the utterance.
- Harris (1951), a pag.185-186, n.63