The noun sooth, pronounced /suːθ/, is now archaic and means ‘fact’,‘reality’ and ‘truth’. Its legacy persists in the words soothe /suːð/, and soothsayer meaning someone who sees the truth, a synonym of fortune teller and the French loanword clairvoyant.
In Shakespeare’s plays, sooth is often used with the verb say and in the expression in sooth whereas truth is often used with the verb tell
From Shakespeare’s Macbeth
If I say sooth, I must report they were
As cannons overcharged with double cracks, so they
Doubly redoubled strokes upon the foe:
(Act I, Scene 2)
And oftentimes, to win us to our harm,
The instruments of darkness tell us truths,
Win us with honest trifles, to betray’s
In deepest consequence.
(Act I, Scene 3)
[Aside] Two truths are told,
As happy prologues to the swelling act
Of the imperial theme.—I thank you, gentlemen.
(Act I, Scene 3)
If thou speak’st false,
Upon the next tree shalt thou hang alive,
Till famine cling thee: if thy speech be sooth,
I care not if thou dost for me as much.
I pull in resolution, and begin
To doubt the equivocation of the fiend
That lies like truth: ‘Fear not, till Birnam wood
Do come to Dunsinane:’…
(Act V, Scene 5)
Merchant of Venice
In sooth, I know not why I am so sad:
It wearies me; you say it wearies you;
(Act I, Scene 1)
Etymonline tells me that truth meaning “something that is true” was first recorded in the mid-14 century. In the 1560s, truth came to mean “accuracy, correctness”. Meanwhile, the noun sooth is dated 900 and was derived from soð.
- I would like to know what difference in meaning, if any, was there between sooth and truth?
- Why did “sooth” become obsolete, and when was it eventually overtaken by “truth”?
World Wide Words appears to suggest that ther is no real difference in meaning between sooth and truth:
Sooth does indeed mean “truth”, an Old English word. It has not been in daily use for about four centuries, except in the phrases by my sooth or my sooth, interjections now obsolete which emphasised that the speaker was telling the truth.
Regarding your second question, it appears the term was commonly used till mid 1600s and has been considered archaic since then.
Archaic in English, it is the root of modern words for "true" in Swedish (sann) and Danish (sand). In common use until mid-17c., then obsolete until revived as an archaism early 19c. by Scott, etc. Used for Latin pro- in translating compounds into Old English, e.g. soðtacen "prodigy," soðfylgan "prosequi."
Sooth was reintroduced in the nineteenth century as a literary archaism by writers such as Sir Walter Scott.
- In sooth, there was that in her face and in her voice when she spoke which almost made Anne weep, through its strange sweetness and radiance.
(A Lady of Quality, by Frances Hodgson Burnett, 1896. This work is exceptionally full of sooth — the author uses the word 20 times.)