A dictionary of Proverbs (Oxford Paperback Reference)

Where IGNORANCE is bliss, ‘tis folly to be wise
Now frequently abbreviated to ignorance is bliss.
Г.17/1Э CD AV Dr>r.Tnr ( 1 OCC A 1 fl Tlir.nnlit t.rr.nl Я rlr.rti-r.Tr 11т nil- mi-nrlirr. Mr. mni-r." nrl-.r.i-r.
uivu oe/miiL( (uuu) ±u inougnt woum uestroy tueir parauise. i^o more; wuere ignorance is bliss, ‘Tis folly to be wise. 1865 SURTEES Facey Romford’s Hounds lxxi. Of course Facey knew nothing about Lucy, and, upon the principle that where ignorance is bliss ‘twere folly to be wise, Soapey was not extra-inquisitive about her. 1925 S. O’CASEY Juno & Paycock II. 49 ‘You ought to be ashamed o’ yourself.. not to know the History o’ your country.’.. ‘Where ignorance’s bliss ‘tis folly to be wise.’ 1983 ‘J. GASH’ Sleepers of Erin i. Antique dealers haven’t a clue. Pathetic. God knows why, but dealers always want to prove that ignorance really is bliss. 2001 TiLes 23 Nov. 20 And the moral of our present situation is: If ignorance is bliss, why aren’t more people happy? ■ignorance
IGNORANCE of the law is no excuse for breaking it
There is a hoary L. legal maxim: ignorantia iuris neLineLexcusat, ignorance of the law excuses nobody.

• 
  c 1412 T. HOCCLEVE De Regimene Principum (EETS) 92 Excuse schal hym naght his ignorance. 1530 C. ST. GERMAN Dialogues in English II. xlvi. Ignorance of the law though it be inuincible doth not excuse. 1616 T. DRAXE Adages 100 The ignorance of the law excuseth no man. a 1654 J. SELDEN Table-Talk (1689) 30 Ignorance of the Law excuses no man; not that all Men know the Law, but because ‘tis an excuse every man will plead, and no man can tell how to confute him. 1830 N. AMES Mariner’s Sketches xxviii. Ignorance of the law excuses nobody. . . The gates of mercy are forever shut against them. 1979 Private Eye 17 Aug. 6 [He] was fined £5 at Marylebone Court when he learned that ignorance of the law is no excuse for breaking it. ■ excuses; law and lawyers