Critical
Part of speech: adjective
Definition: Inclined to find fault or criticize; fastidious; captious; censorious; exacting. Pertaining to, or indicating, a crisis or turning point. Extremely important. Relating to criticism or careful analysis, such as literary or film criticism. Of a condition involving unstable vital signs and an unfavorable prognosis. Likely to go out of control if disturbed, that is, opposite of stable. Of the point (in temperature, reagent concentration etc.) where a nuclear or chemical reaction becomes self-sustaining.
Example sentence: Every single university student should study philosophy. You need to lead the examined life and question your beliefs. If you don't learn critical thinking, then political debate degenerates into a contest of slogans.
Discriminative
Part of speech: adjective
Definition: which has the ability to discriminate between things; or which imparts such abilitywhich serves to distinguish its bearer