Many conceptual categories are parts of dichotomous (distinct and mutually exclusive) pairs: good or bad, right or wrong, rational or irrational, etc  However, advances in scientific understanding have shown some long-held dichotomies to be untenable  Some life forms have characteristics of both animals and plants; also, matter can be converted into energy and vice versa
Ttherefore, dichotomous classifications into mutually exclusive categories should generally be abandoned
Recent clinical trials have shown that some antianxiety drugs are addictive and can have life-threatening side effects. Ttherefore, the use of drugs for the treatment of anxiety should be discontinued.