I wrote previously about the evil of special pleading. There is a related, complementary evil to be found in false equivalence.
False equivalence is treating two things as the same when they clearly are not. But that description of false equivalence could mislead us — it’s important not to get confused here with the use of analogies or illustrations, because that’s another, separate matter.
Analogies or illustrations take two things that are different in order to draw attention to what is similar, so that what is difficult to understand in the one is made easier by seeing it as if in miniature in the corresponding image. A dishonest thinker will tear down every undesired illustration simply by pointing out that the two things are different; but we all know they’re different, and the goal is to be able to learn from their similarities.
False equivalence is another thing altogether. False equivalence (in the sort of instance that I have in mind) says, “If you get to accuse me then I should get to accuse you right back. Any credibility or sympathy that they get should automatically apply to us as well.” Such statements may well be true, depending on the circumstance, but often they are not. Often they are terribly untrue.
An example of this that will seem obvious to some, and for others perhaps doubtful, is socialism and racism (as approximate placeholders for far left and far right in today’s political imagination). It’s true that communist governments and fascist governments have each done evil things. It is not thereby true, however, that socialism and racism are equally evil and should be treated as being on the same footing.
Socialists are concerned about problems related to economic injustice and inequality, to the proper distribution of economic value. This can be pursued poorly or foolishly or dangerously, no doubt, but the goal is a good one. What good goal does a literal racist, qua racist, aim to achieve?
Don’t assume that two things, two sides, two extremes, two enemies, two accounts, are equally valid and should be treated alike. Very often they are not, and shouldn’t be, and then to do so (or to demand it) is nothing but foolishness and falsehood.