In the 1st century ., a fanatical sect arose in Judaea to oppose the Roman domination of Palestine. Known as the Zealots, they fought their most famous battle at the great fortress of Masada, where 1,000 defenders took their own lives just as the Romans were about to storm the fort. Over the years, zealot came to mean anyone who is passionately devoted to a cause. The adjective zealous may describe someone who's merely dedicated and energetic ("a zealous investigator", "zealous about combating inflation", etc.). But zealot (like its synonym fanatic ) and zealotry (like its synonym fanaticism ) are used disapprovingly—even while Jews everywhere still honor the memory of those who died at Masada.
This process has been studied extensively in social psychology as implicit associations and implicit attitudes , a component of implicit cognition . Implicit attitudes are evaluations that occur without conscious awareness towards an attitude object or the self. These evaluations are generally either favorable or unfavorable. They come about from various influences in the individual experience.  Implicit attitudes are not consciously identified (or they are inaccurately identified) traces of past experience that mediate favorable or unfavorable feeling, thought, or action towards social objects.  These thoughts, feelings or actions have an influence on behavior of which the individual may not be aware. 
Diaz-Paniagua has noted that, to "...create an effective legal regime against terrorism, it would be necessary to formulate a comprehensive definition of that crime that, on the one hand, provides the strongest moral condemnation to terrorist activities while, on the other hand, has enough precision to permit the prosecution of criminal activities without condemning acts that should be deemed to be legitimate.  Nonetheless, due to major divergences at the international level on the question of the legitimacy of the use of violence for political purposes, either by states or by self-determination and revolutionary groups, this has not yet been possible."  In this sense, M. Cherif Bassiouni notes: