For it is undeniable that it is much the most difficult to find either propositions to maintain, or arguments to prove them–to know, in short, what to say, or how to say it–on any subject on which one has hardly any information, and no interest; about which he knows little, and cares still less.

Now the subjects usually proposed for School or College-exercises are (to the learners themselves) precisely of this description.

Richard Whately, Elements of Rhetoric