All analogies always break. This is because they are comparisons of things that are not the same, and thus at some point the differences will emerge. This is true of even the best analogy. Nevertheless, analogies remain essential tools for reasoning because in life we generally have to make decisions about things that are not the same. Even standardized industrial products -- blue jeans, say, from a particular manufacturer and in a particular size and style -- will differ in slight ways, and certainly can differ in important properties (e.g., ownership: that one is yours, and this one is mine, and you are not free to dispose of mine as you are your own).
So when we are reasoning analogically, the thing to look for is the place (or places) where the analogy fails to hold. Then we have to see if the conclusion being drawn comes before, or after, the point of disanalogy.
For example, in today's impeachment hearings, Professor Karlan
made an analogy to explain why she thought the President's conduct was impeachable.
Imagine living in a part of Louisiana or Texas that’s prone to devastating hurricanes and flooding. What would you think if you lived there and your governor asked for a meeting with the president to discuss getting disaster aid that Congress has provided for? What would you think if that president said, “I would like you to do us a favor? I’ll meet with you, and send the disaster relief, once you brand my opponent a criminal.”
Wouldn’t you know in your gut that such a president has abused his office? That he’d betrayed the national interest, and that he was trying to corrupt the electoral process?
There are three points of disanalogy that leap out at me. Unfortunately for Dr. Karlan, all of the breaking points occur before the analogy could bear the weight she is trying to put on it.
1) She is analogizing to a 'quid pro quo' situation of exactly the kind that the last months of inquiry have not shown to have taken place. The closest we got to that was Amb. Sondland testifying that he had kind of understood that to be the situation, but that no one in the administration -- indeed, not on the whole planet -- had told him that it was the case. This is somewhat like a prosecutor who has failed to prove that a wrongful killing has happened trying to convince the jury with an analogy to a murder. "Wouldn't it be wrong if it
had been murder? Wouldn't you know in your gut
that was wrong?"
2) A President of the United States has a formal duty to provide disaster relief to Texas or Louisiana that is much stronger than the analog case, treating a foreign country. Even if you want to argue that the President had a particular duty to provide this aid, since Congress had apportioned it, the duty is of a different kind. To refuse to help Americans in need would be a basic betrayal of loyalty in a way that pressuring a foreign government is not.
3) Her 'brand him a criminal' is disanalogous to 'open a formal investigation on this apparently corrupt action, working with the Attorney General as is in accord with our formal treaty governing such investigations.' It's not the same thing at all. The one thing is slanderous, perhaps; the other, given the strong appearance of corruption in the Hunter Biden matter, is a perfectly reasonable exercise of constitutional power by the duly elected officer charged with exercising that power.
It's a pretty sad spectacle. I hope she's a better professor about matters where she is less passionate. Passion is the enemy of reason as we all know, and as Professor Turley rightly pointed out in a far better set of testimony.