Sentence:  Recognizing that the Rule of Law <WSD>is</WSD> `` a dynamic concept which should be employed not only to safeguard the civil and political rights of the individual in a free society '' , the Congress asserted that it also included the responsibility `` to establish social , economic , educational and cultural conditions under which his legitimate aspirations and dignity may be realized '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)