Abstract：Evolutionary Contingency Thesis which proposed by John Beatty, indicates that biological generalizations which are true only under accidental initial conditions are all accidental generalizations, and laws aren’t accidentally true,so biological generalizations never can be regarded as laws. Aimed to this thesis, a viewpoint offered by Elliot Sober and supported by Mehmet Elgin holds that the compound generalizations consisting of accidental initial conditionsand accidental generalizations may be regarded aslaws rather than accidental generalizations. Their viewpoint has been criticized as facing two problems: it makes all biological generalizations possible to be regarded as laws; it removes the distinction between laws and accidental generalizations. However, as long as their viewpoint is developed into “a compound generalizationwhich can play the function of law may be a law”, then these two problems can be effectively solved.

Keyword：Evolutionary contingency thesis; Accidental generalizations; Initial conditions; Modal force