Political Science is an observational science. When observation and comparison are undertaken regarding things of the past, it becomes the Historical Method. It supplements the experiment method, because history is but an experiment made in die past. Thus Historical Method combines die advantages of three methods, namely, those of observation, comparison and experimentation or experience. Prof Gilchrist aptly remarks, “The source of experiments of Political Science is history; they rest on observations and experience. Every change in the form of government, every law, every war in the past is an experiment in Political Science.”<\/p>