自然性原则 a 1: A reconstructed language should be a natural synchronic system from which known later stages can be derived by natural diachronic process. a 2: Since many hypotheses may be consistent with our knowledge at any given time, it is best to check first those hypotheses that are typologically least unusual 1313 自然性原则 † 1: A reconstructed language should be a natural synchronic system from which known later stages can be derived by natural diachronic process. † 2: Since many hypotheses may be consistent with our knowledge at any given time, it is best to check first those hypotheses that are typologically least unusual