abstract concept

Translations
абстрактная концепция
The idea of freedom is often considered an abstract concept.
Идея свободы часто считается абстрактной концепцией.
Definitions
An abstract concept is an idea or notion that does not have a physical or concrete existence, often representing qualities, ideas, or relationships that cannot be directly observed or measured, such as love, freedom, or justice.
Words
concept

noun
концепция
abstract

adjective
абстрактный