If two political parties A and B have competing public policy proposals, and you criticize party A's proposal, it is typically a fallacy for your listener to assume that you therefore favor B's proposal. (The only exceptions are those simplistic cases in which Party B is simply opposing A's proposal, as when one party on the town council proposes to put a traffic light on Main Street and another party opposes doing so.) The fallacy lies in the fact that there are typically possible policies different from both A's and B's. (Even in the case of the traffic light dispute, a third party might propose installing a stop sign.) Complicated and interesting public policy disputes might give rise to dozens of viable, competing proposals. This fallacy could be labeled 'false dichotomy' or 'false dilemma'. In the classic instances of this fallacy an arguer presents an either-or choice, and then concludes that one ought to believe or perform one of the disjuncts, when in fact there are more than the two...

Too often people offer sympathy in ways that make themselves feel better at the expense of the target of their ostensible kindness. To tell someone who is suffering "That's not so bad -- I've had it much worse" reassures the speaker about his or her own fortitude in the face of misfortune, but it displays gross insensitivity to the plight of the person suffering in the here and now (even if the speaker is right about their respective degrees of suffering). In saying that the victim's suffering is less than the victim thinks it is, the ostensible sympathizer withholds a full acknowledgement of that suffering. (Contrast that insensitive remark with something like: "I can imagine the pain you are in. I remember how much it hurt when I broke my leg.") In some situations, however, a remark like "Other people have it much worse than you" might be appropriate. If your friend is complaining excessively about not receiving a promotion that she wanted, it might be appropriate to remind her that, well, she...

As logicians and contemporary philosophers use the word 'valid', a valid argument (or piece of reasoning) is one such that it is impossible for the premises to be true and the conclusion false. The primary task of symbolic logic is to determine which arguments are valid; logicians pursue this goal by providing rules and techniques for evaluating the validity of argument forms. Any instance of a valid argument form -- that is, any particular piece of reasoning that has that form -- is valid. A valid syllogism -- or more generally any valid argument -- can exhibit no fallacy. (We may provisionally define 'fallacy' as a defect in an argument other than false premises.) In the examples you are worried about, we have arguments that appear to possess a valid form, but really do not. Here is a valid form: Thing A has property P. Thing B is identical to Thing A. Therefore, Thing B has property P. Your first two examples seem to have this form, and it seems that their premises...