Now commonly used to assert that a placid exterior hides a passionate or subtle nature. Cf. [Q. Curtius De Rebus Gestis Alexandri Magni VII. iv. 13] altissima quaeque flumina minimo sono labi, the deepest rivers flow with least sound [said there to be a Bactrian saying].
There the flode is deppist the water standis stillist.
[c 1400 Cato's Morals in Cursor Mundi (EETS) 1672]
Smothe waters ben ofte sithes [oftentimes] depe.
[c 1410 J. Lydgate Minor Poems (EETS) 476]
Where riuers runne most stilly, they are the deepest.
[1616 T. Draxe Adages 178]
Smooth Waters run deep.
[1721 J. Kelly Scottish Proverbs 287]
In maturer age‥the fullest, tenderest tide of which the loving heart is capable may be described by those ‘still waters’ which ‘run deep’.
[1858 D. M. Mulock Woman's Thoughts about Women xii.]
As for her, still waters run deep, it seems. She always looked so solemn. ‥Fancy her shooting him!
[1979 M. Underwood Victim of Circumstances ii. 86]
Still waters run deep, so they say. The stillest and deepest belonged to Greta Garbo, who abruptly ended a dispute with Hollywood's moguls by saying, ‘I tink I go home now.’ She meant Sweden.
[2001 National Review 30 Apr. 60]
Related to: appearance, deceptive; speech and silence
Bibliography of major proverb collections and works cited from modern editions is available here.




