The definite article is used:

#1. With nouns modified by adjectives in the superlative degree.

Miss Tox had the softest voice that ever was heard. (Dickens)

#2. with nouns in word-groups the first component of which is some, many, none, most and the second a noun with the preposition of.

Most of the gentlemen looked both angry and uncomfortable. (Voynich)

#3. with nouns modified by the pronoun same and the adjectives wrong, right, very.

То all invitations he replied with the same courteous and positive refusal. (Voynich)

I do wish we had not opened the door of the wrong room. (Jerome)

“Ah! Mr. Burton!” exclaimed the Director, “the very person I wanted.” (Voynich)

Signora Grassini hated Gemma for the very expression of her face.

#4. with substantivized adjectives and participles.

Only the simple and the humble were abroad at that early hour. (Bennett)

 Grey conveyed some of his love of the beautiful to Cowperwood. (Dreiser)

The listeners noted something beyond the usual in his voice. (Galsworthy)

Note — With countable abstract nouns the use of the articles is the same as with class nouns.

It is a capital idea if only one could carry it out. (Voynich)