Special remarks on adverbs of degree.
283. The is an adverb of degree when it limits an adjective or an adverb, especially the comparative of these words; thus,—
But not the less the blare of the tumultuous organ wrought its own separate creations.—De Quincey.
The more they multiply, the more friends you will have; the more evidently they love liberty, the more perfect will be their obedience.—Burke.
This and that are very common as adverbs in spoken English, and not infrequently are found in literary English; for example,—
The master...was for this once of her opinion.—R. LOUIS STEVENSON.
Death! To die! I owe that much To what, at least, I was.—Browning.
This long's the text.—Shakespeare.
[Sidenote The status of such.]
Such is frequently used as an equivalent of so: such precedes an adjective with its noun, while so precedes only the adjective usually.