The definite article for substantivation of adjectives

Any adjective can be converted in a noun by putting a definite article before. (Although in English one has to added; blue => the blue one.) In Portuguese the article has to agree in gender and number with the noun it refers two. Given that in english there is only one definitive article, that doesn't make any difference in english.

substantivation of adjectives
I don't like the blue one. (Refers for instance to a pencil.)
I don't like the blue ones. (Refers for instance to trousers.)

That is this simple and works the same way in Portuguese.

Sãoos ambiciosos que fazem o mundo girar.
Are the ambitious who make the world turn.
The ambitious make the world go round.

Você prefere as mulheres bonitas ou as inteligentes?
You prefer the women beautiful or the intelligent?
Do you prefere the intelligent woman or the beautiful women.

As pessoas pobres sãomais gordasque as ricas.
The persons poor are more thick than the rich.
Poor people are thicker than rich people.

Construction like the happy, the beautiful, the poor etc.. refers to a property of the referenced noun. The happy are all the people who have this property. One property is constitutive for the noun. The same thing happens with the catholics, the moslems, the butchers etc.. However in most languages a distinction is to be made between feminine and masculine, singular or plural.

It is possible as well to refer to the property itself. In the sentence "the good in human beings" the good refers to nothing. It is an abstract notion that needs to be specified, but it doesn't refer to someone who has this property.

1) The good (people / bananas) can be worse than the evil (people / bananas).
2) He believes in the good of human nature.

In 1) we have a property of someone / someone. In 2) we refer to the property itself.

In masculine / singular, o bom, the good, is therefore ambiguous. It can refer to the constitutive property of someone / something or to the property itself. (Spanish is different concerning this issue. Spanish has a neutral definitive article, lo: el bueno = the good (property of a person) <=> lo bueno = the good (refers to the property itself)

Copiar o bom é melhor que inventar o ruim.
To copy the good is better than to invent the bad.

O belo nutre o espírito e o ilumina.
The beautiful nourish the spirit and it enlighte.
The beautyiful nourish the spirit and enlighte it. .

O estranho é como um quarto escuro em que não vemos nada.
The strange is like a room dark in which not we see nothing.
The unknownn is like a dark room in which we see nothing.

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