WordNet (r) 3.0 (2006):

mechanistic
    adj 1: explained in terms of physical forces; "a mechanistic
           universe"
    2: of or relating to the philosophical theory of mechanism

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "mechanistic":
   Cyrenaic, Eleatic, Epicurean, Marxian, Marxist, Megarian, Stoic,
   aeromechanical, animist, animistic, atomistic, biomechanical,
   commonsense, cosmotheistic, eclectic, empirical, eudaemonistic,
   existential, hedonic, hedonist, hedonistic, humanist, humanistic,
   hylomorphous, hylotheistic, idealistic, instrumentalist,
   locomotive, locomotor, materialist, materialistic, mechanical,
   mechanist, metaphysical, monistic, naturalist, naturalistic,
   nominalist, panlogistical, pantheistic, positivist, positivistic,
   pragmatic, pragmatist, rationalistic, realist, realistic,
   scholastic, sensationalistic, syncretistic, theistic,
   transcendentalist, transcendentalistic, utilitarian, vitalistic,
   voluntarist, voluntaristic, zoomechanical