jurisprudence (n.)

mid-15c., "one who practices law;" 1620s, "a legal writer, one who professes the science of the law," from French juriste (14c.), from Medieval Latin iurista "jurist," from Latin ius (genitive iuris) "a right," especially "legal right or authority, law," also "place where justice is administered, court of justice," from Old Latin ious, perhaps literally "sacred formula," a word peculiar to Latin (not general Italic) that originated in the religious cults, from PIE root *yewes- "law" (compare Latin iurare "to pronounce a ritual formula," Vedic yos "health," Avestan yaoz-da- "make ritually pure," Irish huisse "just"). Related: Juristic. The more mundane Latin law-word lex meant specific laws as opposed to the body of laws.

The Germanic root represented by Old English æ "custom, law," Old High German ewa, German Ehe "marriage," sometimes is associated with this group, or it is traced to PIE *ei- "to go."

mid-14c. (c. 1200 as a surname), "intelligence; discretion, foresight; practical wisdom to see what is suitable or profitable;" also one of the four cardinal virtues, "wisdom to see what is virtuous;" from Old French prudence (13c.) and directly from Latin prudentia "a foreseeing, foresight, sagacity, practical judgment," contraction of providentia "foresight" (see providence, which is a doublet). The secondary sense of "knowledge, science" (late 14c.) is preserved in jurisprudence.