Posterior parietal cortex (PPC) activity correlates with monkeys’ conclusions during visual discrimination and categorization tasks. Yet, recent work has questioned if decision-correlated PPC action plays a causal role in such decisions. That research concentrated on PPC’s contribution to motor aspects of conclusions (deciding where to proceed ), but not neurological investigation facets (determining what you are looking at). We used reversible inactivation to compare PPC’s donations to sensory and motor elements of decisions. Inactivation influenced both facets of behavior, but preferentially impaired conclusions when visual stimulation, instead of motor response goals, have been in the inactivated visual discipline. This shows a causal role for PPC in conclusion, together with preferential involvement in evaluating attended task-relevant sensory stimuli in comparison with motor preparation.