The truth table method, natural deduction, and the truth tree method, the three validity proving methods standardly taught in an introductory logic course, are too clumsy for the battlefield of real-life. The “short truth table” test is handy at times, but it stumbles at many other times. In this paper, we set up a general method that can beat all the methods mentioned above in a contest of speed. Furthermore, the procedure can be step-by-step paraphrased in a natural language, so (...) that, unlike the other methods, a real-life logical problem can be analyzed and explained in a real-life language too. (shrink)

In ‘What Makes Killing Wrong?’ Sinnott-Armstrong and Miller make the bold claim that killing in itself is not wrong, what is wrong is totally-disabling. In ‘After-Birth Abortion: Why Should the Baby Live?’ Giubilini and Minerva argue for allowing infanticide. Both papers challenge the stigma commonly associated with killing, and emphasize that killing is not wrong at some margins of life. In this paper, we first generalize the above claims to the thesis that there is nothing morally wrong with killing per (...) se, so long as it is instant and unannounced. Then, from the perspective of social evolution, we explain why people refrain from killing others, the general guideline being that it is unadvisable to kill someone with whom you associate a Second Person Perspective (SPP). Finally, drawing from a seminal paper of Press and Dyson on the Iterated Prisoner’s Dilemma, we stress that an SPP without an SP (Second Person), or the other way around, can both lead to unwelcome results. (shrink)