 First let us delimit our field. The examples with which we began are traditionally called “indicative conditionals”. There are also “subjunctive” or “counterfactual” conditionals like “Tom would have cooked the dinner if Mary had not done so”, “We would have been home by ten if the train had been on time”. Counterfactuals will be the subject of a separate entry, and theories addressing them will not be discussed here. That there is some difference between indicatives and counterfactuals is shown by pairs of examples like “If Oswald didn’t kill Kennedy, someone else did” and “If Oswald hadn’t killed Kennedy, someone else would have”: you can accept the first yet reject the second (Adams (1970)). That there is not a huge difference between them is shown by examples like the following: “Don’t go in there”, I say, “If you go in you will get hurt”. You look sceptical but stay outside, when there is large crash as the roof collapses. “You see”, I say, “if you had gone in you would have got hurt. I told you so.” 