Mechanism and Vitalism are opposing philosophical views on life: Mechanism sees living things as complex machines explainable by physics/chemistry (parts, interactions), while Vitalism insists life needs a non-physical "life force" (soul/spirit) beyond matter. This historical debate, central to biology, shifted with modern science; vitalism faded as chemistry synthesized organic molecules (like urea), proving forces aren't exclusive to life, yet modern biology integrates mechanistic explanations with system dynamics, acknowledging life's holistic, self-regulating aspects, moving beyond simple machine analogies.