Bob's blog – A skeptical lawyer

One-sided assessment – Opie Taylor and John Stuart Mill

Posted on February 17, 2018




In The Andy Griffith Show, Opie Taylor learned a lesson about honesty when he tried to sell his bike to another kid without revealing several mechanical defects. Andy put a spoke in Opie’s wheel by disclosing said defects. Andy explained, “If you’re selling something, the buyer has a right to know everything wrong with it. Otherwise, it’s not quite honest.” Andy taught his son to be truthful, but notice that nobody had to teach Opie to conceal his bike’s glitches. Children intuitively understand how to put a positive spin on a situation by leaving out the bad stuff.

It is human nature to soft-pedal our weaknesses, but disregarding contrary arguments may also be a logical fallacy. Presenting half-truths as if they were the whole truth makes a defective argument appear to be valid. People use many names for this pervasive fallacy. Mark Twain called it the silent-assertion lie. In politics, we call it “spin.” Some people use the label cherry picking, but that term most often refers to choosing data selectively to support a desired result. In the context of legal argument, I prefer the term “one-sided assessment.”

Trial lawyers may present one-sided arguments in court, and then the judge or jury decides after hearing both sides. However, an effective advocate does not merely ignore contrary arguments or damaging evidence. A lawyer may find it difficult to analyze and discuss the weaknesses in his own case, but a strong advocate must face the music. “The most telling discovery a judge can make is that a brief has neglected to deal with an issue.”[i] If a lawyer cannot respond to his opponent’s arguments, then the judge and jury may justifiably assume that the opponent’s arguments are correct.

In his essay, On Liberty, English philosopher John Stuart Mill discussed why a thinking person must consider opposing viewpoints in order to understand the truth of any issue. Most people will probably be too damn lazy to read the following quote, but I encourage you to take the time and really think about it.

The peculiarity of the evidence of mathematical truths is that all the argument is on one side. There are no objections, and no answers to objections. … But when we turn to subjects infinitely more complicated, to morals, religion, politics, social relations, and the business of life, three-fourths of the arguments for every disputed opinion consist in dispelling the appearances which favour some opinion different from it. … He who knows only his own side of the case knows little of that. His reasons may be good, and no one may have been able to refute them. But if he is equally unable to refute the reasons on the opposite side; if he does not so much as know what they are, he has no ground for preferring either opinion. The rational position for him would be suspension of judgment, and unless he contents himself with that, he is either led by authority, or adopts, like the generality of the world, the side to which he feels most inclination. Nor is it enough that he should hear the arguments of adversaries from his own teachers, presented as they state them, and accompanied by what they offer as refutations. That is not the way to do justice to the arguments, or bring them into real contact with his own mind. He must be able to hear them from persons who actually believe them; who defend them in earnest, and do their very utmost for them. He must know them in their most plausible and persuasive form; he must feel the whole force of the difficulty which the true view of the subject has to encounter and dispose of; else he will never really possess himself of the portion of truth which meets and removes that difficulty.


Ruggero Aldisert, Logic for Lawyers, A Guide to Clear Legal Thinking 20 (Third Ed. 1997).

Karl Llewellyn, The Common Law Tradition, Deciding Appeals 85 (1960). Jack Landau, Logic for Lawyers, 13 Pac. L.J. 59, 93 (1981).

McClurg, Logical Fallacies and the Supreme Court: A Critical Examination of Justice Rehnquist’s Decisions in Criminal Procedure Cases, 59 U. Colo. L. Rev. 741, 786 (1988).

McClurg, The Rhetoric of Gun Control, 42 Am. U.L. Rev. 53, 97 (1992).

Underwood, Logic and the Common Law Trial, 18 Am. J. Trial Advoc. 151, 181 (1994).

[I] Frank M. Coffin, The Ways of a Judge 104 (1980).