Dorian Gray ch. 1-2

"Now, the value of an idea has nothing whatsoever to do with the sincerity of the man who expresses it. Indeed the probabilities are that the more insincere the man is, the more purely intellectual will the idea be, as in that case it will not be colored by either his wants, his desires, or his prejudices" (11)

Lord Henry makes a valid point here that relates back to the preface. As Wilde mentioned in the preface, beauty must be recognized for beauty's sake without the influence of external sources to corrupt one's opinion. Similarly, one's emotions take away from the intellectual state of an idea. The more feelings get involved with a theory, the more it becomes invalid. An objective third party is often useful to solve a dispute because they will give an unbiased answer without any emotions being involved. Factual evidence is the best method for supporting an argument because being led by your emotions leads to supplying opinionated ideas that can make you sound foolish and unintelligent in the end.