Home › Topics › Knowledge & Understanding Topic Knowledge & Understanding 5 maxims cross-cutting the 12 books 3.4.1 Discretion is to know through the law what is just. Discretio est scire per legem quid sit justum. Source: 10 Co. 140; Weisman, 69a True discretion is not personal preference — it is the informed application of settled legal principles to the facts at hand. 3.4.2 By reasoning we arrive at lawful reason. Ratione pervenitur ad legitimam rationem. Source: Litt. s. 386; Co. Litt. 232b Legal conclusions must be reached through a chain of reasoning traceable to established principles — not by decree or arbitrary assertion. 3.4.3 To know the laws is not to hold to their mere words, but their force and power. Scire leges non hoc est verba earum tenere, sed vim ac potestatem. Source: Dig. 1, 3, 17; 1 Kent, Comm. 462; Weisman, 69m The letter of the law must yield to its spirit when the two conflict — he who grasps only the words without the meaning knows nothing. 3.4.4 To know and to be bound to know are regarded in law as equivalent. Scire et scire debere aequiparantur in jure. Source: Tray. Leg. Max. 551; Bouvier, Law Dict. 129; Weisman, 69l Constructive knowledge is as potent as actual knowledge. One who should have known the law or the facts is treated as if he did know them. 3.4.5 Equal knowledge on both sides makes the contracting parties equal. Scientia utrinque par pares contrahentes facit. Source: 3 Burr. 1910; Broom, Max. 774; Jackson, Lat. for Law. no. 959; Weisman, 24o A contract formed where one party withholds material knowledge from the other is not a contract between equals — and may be voidable for that disparity.