The Collaborative International Dictionary of English v.0.48:
Mechanist \Mech"an*ist\, n. 1. A maker of machines; one skilled in mechanics. [1913 Webster] 2. One who regards the phenomena of nature as the effects of forces merely mechanical. [1913 Webster]WordNet (r) 3.0 (2006):
mechanist n 1: a philosopher who subscribes to the doctrine of mechanism