ḱrey-sis-
“act of separating, judgment”crisis, criterion, critic, critique
Abstract from *krey- giving Greek krisis, English crisis, criterion, critic, critique, hypocrisy.
Discussion
The PIE form *ḱrey-sis- (act of separating, judgment) is an action noun from the verbal root *ḱrey- (to sieve, to separate, to distinguish), formed with the abstract suffix *-sis- that produces nouns of process. The literal meaning is "the act of separating" — and from this single concept of separation emerged an entire vocabulary of judgment, decision, and critical thought.
Greek krísis (κρίσις, "decision, judgment, turning point") is the direct continuation, and it entered English virtually unchanged as crisis — a moment of decisive separation, a point where outcomes diverge. The Greek verb krínein (to judge, to decide, to separate) generated: criterion (κριτήριον, the standard by which separation/judgment is made), critic (κριτικός, one who judges), critique, and critical. The medical sense of crisis — the turning point of a disease, where the patient either recovers or dies — preserves the original Greek clinical usage found in Hippocratic texts.
The semantic chain from "sieve" to "judge" is not metaphorical accident but conceptual logic: to judge IS to separate, to sift the true from the false, the good from the bad, the relevant from the irrelevant. English still preserves this connection in the word discern (from Latin dis-cernere, "to separate apart"), which means both "to perceive" and "to judge" — perception and judgment as acts of separation.
Latin cernere (to sift, to separate, to decide) continues the root with the expected Italic treatment: *ḱ > Latin c. The past participle crētus (separated, decided) gave English concrete (grown together — wait, that is *ḱerh₂-; the relevant Latin derivative is discreet/discrete, from discrētus, "separated apart"). The legal term decree (from dē-cernere, "to decide from") and the word secret (from sē-cernere, "to separate apart, to set aside") both embed the separation metaphor.
Crime itself descends from this root: Latin crīmen ("charge, accusation, offense") is from *ḱrey-mn̥, literally "a separation, a judgment" — a crime is that which has been judged, the act that has been separated out as wrongful. The word criminal, incriminate, and discriminate (to separate between) all continue the chain.
The Vedic Sanskrit cognate cinátti ("he gathers, separates, selects") preserves the root in the Indo-Iranian branch with the expected satem treatment (*ḱ > Sanskrit c/ś). The related noun citi- ("gathering, arrangement") appears in ritual contexts.
The productivity of this single root — sieve → separate → judge → decide → accuse — demonstrates how PIE verbal semantics could generate entire conceptual domains. From the concrete act of sifting grain, PIE speakers abstracted the concept of discrimination, and their linguistic descendants built the vocabularies of law, medicine, philosophy, and literary criticism on that foundation.