RELATIVAL CONSTRUCTIONS. "So--as:" "as--as"--So as. Bearing in mind that as is simply a contraction for "all-so" ("alse," "als," "as"), we shall not be surprised at some interchanging of so and as. We still retain "as . . . so": "As I had expected so it happened," but seldom use "so . . . as," preferring "as . . . as;" except where so (as in the above phrase) requires special emphasis. The Elizabethans frequently used so before as.
“So well thy words become thee as thy wounds.
“Look I so pale, Lord Dorset, as the rest?
“And with a look so piteous in purport
As if he had been loosed out of hell.
“Fair and fair and twice so fair
“Thou art so full of fear
As one with treasure laden.
As any shepherd may be.” PEELE.
This is not very common in Shakespeare. Nor is it common to find so for as where the clause containing the second as is implied but not expressed.
“All so soon as.
If the relatival as precedes, so, not as, must follow as the demonstrative. The exception below is explicable as being a repetition of a previous as used demonstratively:
“Make us partakers of a little gain,
That now our loss might be ten times so much.
"That" is the relative. Ben Jonson (p. 789) writes as follows on so and as: "When the comparison is in quantity, then so goeth before and as followeth. “Men wist in thilk time none
“As little joy, my lord, as you suppose
You should enjoy, were you this country's king,
As little joy may you suppose in me
That I enjoy.
So fair a wight as she was one.” GOWER, lib. 1. But if the comparison be in quality, then it is contrary. “For, as the fish, if it be dry,
Mote, in default of water dye:
Right so without air or live,
No man ne beast might thrive.” GOWER." So as is frequently used for so that. (See 109.) This construction is generally found with the past and future indicative, but we sometimes find "so as he may see," for "so that he may see." "So as" is followed by the subjunctive in
Compare the use of ὡς with the subjunctive in Greek. There is no more reason for saying, "I come so that (i.e. in which way) I may see," than for saying, "I come so as (i.e. in which way) I may see." We sometimes find so as that for so as in this sense. The so is omitted after as in the adjurations
“And lead these testy rivals so astray
As one come not within another's way.
where as means "in which degree," and so "in that degree." Hence as approximates to "if." It would seem that "as . . . so" are both to be implied from the previous verse in
“As ever thou wilt deserve well at my hands, (so) help me to a
“Had you been as wise as bold,
（As) young in limbs, (so) in judgment old.