1 00:00:02,600 --> 00:00:06,696 Welcome back. We've covered stages one through three of 2 00:00:06,696 --> 00:00:12,430 argument reconstruction namely, close analysis, get down to basics, and sharpen 3 00:00:12,430 --> 00:00:15,781 edges. In this lecture, we'll cover stage four, 4 00:00:15,781 --> 00:00:21,293 which is organized parts. because it's not enough to isolate the parts and 5 00:00:21,293 --> 00:00:27,250 figure out what they are. We need to show how the fit together in a structure so 6 00:00:27,250 --> 00:00:32,166 that they work together to support the conclusion of the argument. 7 00:00:32,166 --> 00:00:35,890 To see how this works, let's start with an example. 8 00:00:35,890 --> 00:00:41,541 Consider this example. That fertilizer won't help the roses bloom because there 9 00:00:41,541 --> 00:00:47,407 is already a lot of nitrogen in the soil. So, the fertilizer will make the nitrogen 10 00:00:47,407 --> 00:00:51,341 levels too high. Of course, so is a conclusion marker so 11 00:00:51,341 --> 00:00:56,850 one conclusion is that, the fertilizer will make the nitrogen levels too high. 12 00:00:56,850 --> 00:01:02,492 And then, you might think that one might have put the argument into standard form 13 00:01:02,492 --> 00:01:06,463 goes like this. Premise one is that fertilizer won't make 14 00:01:06,463 --> 00:01:10,504 the roses bloom. Premise two is the nitrogen levels in the 15 00:01:10,504 --> 00:01:14,196 soil are already high. And then, the conclusion is that the 16 00:01:14,196 --> 00:01:17,680 fertilizer will make the nitrogen levels too high. 17 00:01:17,680 --> 00:01:22,441 But that doesn't really make any sense, if you think about it. How could the fact 18 00:01:22,441 --> 00:01:27,382 that the roses won't bloom be a reason to believe that the nitrogen levels are too 19 00:01:27,382 --> 00:01:30,754 high? This couldn't be a reason for that. So, 20 00:01:30,754 --> 00:01:35,504 we might just have the wrong structure. However, there is another argument 21 00:01:35,504 --> 00:01:38,837 marker. This time it's a premise marker, because. 22 00:01:38,837 --> 00:01:44,509 And that indicates that the claim that there's already a lot of nitrogen in the 23 00:01:44,509 --> 00:01:48,338 soil is a premise. But what is the conclusion for that 24 00:01:48,338 --> 00:01:51,245 premise? That's supposed to show that the 25 00:01:51,245 --> 00:01:57,225 fertilizer won't make the roses bloom. So, we've missed that part of the 26 00:01:57,225 --> 00:02:01,805 structure if we put it in standard form, the way we first thought. 27 00:02:01,805 --> 00:02:05,750 The trick here is that there are really two conclusions. 28 00:02:05,750 --> 00:02:11,176 One conclusion is that the fertilizer won't help the roses bloom, and another 29 00:02:11,176 --> 00:02:16,800 conclusion is that the fertilizer will make the nitrogen levels too high. 30 00:02:16,800 --> 00:02:20,995 But each argument's just supposed to have one conclusion. 31 00:02:20,995 --> 00:02:24,381 So, how are we going to put this into a structure? 32 00:02:24,381 --> 00:02:27,693 The solution is that there are two arguments. 33 00:02:27,693 --> 00:02:32,184 One is that the nitrogen levels in the soil are already high. 34 00:02:32,184 --> 00:02:36,306 Therefore, adding the fertilizer will make them too high. 35 00:02:36,306 --> 00:02:41,973 And the second argument is that, adding the fertilizer will make the nitrogen 36 00:02:41,973 --> 00:02:47,200 levels too high, therefore the fertilizer will not make the roses bloom. 37 00:02:48,220 --> 00:02:53,403 Now notice that one argument really builds on the other because the 38 00:02:53,403 --> 00:02:59,196 conclusion of the first argument is really a premise in the second argument. 39 00:02:59,196 --> 00:03:03,083 So, we can represent them as two separate arguments. 40 00:03:03,083 --> 00:03:06,513 But we can also put them together in a chain. 41 00:03:06,513 --> 00:03:11,239 So that the argument says, the nitrogen levels in the soil are 42 00:03:11,239 --> 00:03:15,126 already high. Therefore, adding fertilizer will make 43 00:03:15,126 --> 00:03:17,261 them too high. And therefore, 44 00:03:17,261 --> 00:03:21,780 adding fertilizer will not help the roses bloom. 45 00:03:21,780 --> 00:03:27,872 Now, if we take that whole structure and we try to represent it in a diagram, and 46 00:03:27,872 --> 00:03:34,346 we represent each premise with a number, which is the number that was given in the 47 00:03:34,346 --> 00:03:40,362 standard form, then we can simply have premise one with an arrow to premise two 48 00:03:40,362 --> 00:03:46,378 indicating that premise one is a reason for premise two. And then, another arrow 49 00:03:46,378 --> 00:03:52,243 going from premise two to premise three to indicate that two is a reason for 50 00:03:52,243 --> 00:03:55,436 three. In a way, we've got two premises and two 51 00:03:55,436 --> 00:04:00,431 conclusions because that one kind in the middle, number two, operates as a 52 00:04:00,431 --> 00:04:05,220 conclusion in the first argument and a premise in the second argument. 53 00:04:05,220 --> 00:04:07,615 But overall, I hope the diagram, its clear. 54 00:04:07,615 --> 00:04:12,267 Well, I want to call this linear structure. When you have one premise 55 00:04:12,267 --> 00:04:17,809 giving reason for a conclusion which is then premise for another conclusion, then 56 00:04:17,809 --> 00:04:22,120 they form a line in the diagram them in the way that I am proposing. 57 00:04:22,120 --> 00:04:27,495 Arguments can have other structures, too. In particular, sometimes there's more 58 00:04:27,495 --> 00:04:31,147 than one premise associated with a single conclusion. 59 00:04:31,147 --> 00:04:35,488 And this can happen in two ways. The first, we're going to call the 60 00:04:35,488 --> 00:04:40,450 branching structure, and the second we're going to call the joint structure. 61 00:04:40,450 --> 00:04:44,160 Here is an example of the branching structure. 62 00:04:44,160 --> 00:04:49,220 I'm not going to go to the movie with you because I don't like horror flicks. 63 00:04:49,220 --> 00:04:50,929 And besides, I'm too busy. 64 00:04:50,929 --> 00:04:56,263 The word because is a premise marker. So that indicates that the conclusion is 65 00:04:56,263 --> 00:04:59,272 that, I'm not going to go to the movie with you. 66 00:04:59,272 --> 00:05:02,896 And there are two premises. One is, I don't like horror flicks, 67 00:05:02,896 --> 00:05:07,819 and the other is, I'm too busy. Now, you might think that, that could 68 00:05:07,819 --> 00:05:11,922 just be put in the old linear structure that we already saw. 69 00:05:11,922 --> 00:05:15,400 But then, the argument's going to look like this. 70 00:05:15,400 --> 00:05:21,303 I don't like horror flicks. Therefore, I'm too busy. Therefore, I'm not going to 71 00:05:21,303 --> 00:05:23,401 go to the movie. But, wait a minute. 72 00:05:23,401 --> 00:05:27,536 The fact that I don't like horror flicks doesn't mean I'm too busy. 73 00:05:27,536 --> 00:05:31,423 That doesn't make any sense. Oh, maybe it's the other way around. 74 00:05:31,423 --> 00:05:35,620 I'm too busy. Therefore, I don't like horror flicks. Therefore, I'm not going 75 00:05:35,620 --> 00:05:39,755 to go to that movie with you. That doesn't make any sense either. 76 00:05:39,755 --> 00:05:43,704 The fact that I'm too busy isn't why I don't like horror flicks. 77 00:05:43,704 --> 00:05:48,579 The problem is, there are two premises here but neither one is a reason for the 78 00:05:48,579 --> 00:05:51,311 other, as we saw in the linear structure. 79 00:05:51,311 --> 00:05:56,591 Instead, in this branching structure, each premise is operating independently. 80 00:05:56,591 --> 00:06:00,471 There's one argument. I don't like horror flicks, therefore I'm 81 00:06:00,471 --> 00:06:04,251 not going to go to that movie with you. There's another argument. 82 00:06:04,251 --> 00:06:07,794 I'm too busy, therefore I'm not going to that movie with you. 83 00:06:07,794 --> 00:06:12,105 And each premise by itself is a sufficient reason not to go to the movie 84 00:06:12,105 --> 00:06:14,231 with you. I mean, just think about it. 85 00:06:14,231 --> 00:06:18,602 If I wasn't too busy, but I didn't like horror flicks, I wouldn't go to the 86 00:06:18,602 --> 00:06:21,259 movie. But if I liked horror flicks, but I was 87 00:06:21,259 --> 00:06:25,925 too busy, I still would go to the movie. So, each premise by itself is enough, and 88 00:06:25,925 --> 00:06:30,582 they operate independently. That's what makes this a branching 89 00:06:30,582 --> 00:06:35,799 structure instead of a linear structure. Let's diagram it and you'll see why we 90 00:06:35,799 --> 00:06:40,382 call it a branching structure. One way to diagram it would be to simply 91 00:06:40,382 --> 00:06:44,307 draw an arrow between premise one and the conclusion two. 92 00:06:44,307 --> 00:06:49,609 And then, there's a separate argument, so you draw another arrow from one star, 93 00:06:49,609 --> 00:06:53,182 another premise, to conclusion two. And that's okay. 94 00:06:53,182 --> 00:06:59,345 But, notice that it doesn't show you that both premises are reasons for the same 95 00:06:59,345 --> 00:07:02,735 conclusion. So, to capture that aspect of the 96 00:07:02,735 --> 00:07:08,128 structure, that both Premise one and Premise one Star support the same 97 00:07:08,128 --> 00:07:13,059 conclusion, namely two. It's better to diagram it so that there's 98 00:07:13,059 --> 00:07:18,914 an arrow that runs independently from both premises to a single instance of 99 00:07:18,914 --> 00:07:22,980 conclusion two, as you see on the diagram on the screen. 100 00:07:22,980 --> 00:07:26,446 And that should show you why we're calling it a branching structure because 101 00:07:26,446 --> 00:07:29,190 it kind of branches, it looks like the branches of a tree. 102 00:07:29,190 --> 00:07:31,212 Okay. Well, it doesn't really look like the 103 00:07:31,212 --> 00:07:34,678 branches of a tree, but you get the idea. We're going to call it a branching 104 00:07:34,678 --> 00:07:37,696 structure. Next, we have to separate this branching 105 00:07:37,696 --> 00:07:41,310 structure from what we're going to call the joint structure. 106 00:07:41,310 --> 00:07:45,812 The difference is that in the branching structure, the premises provide 107 00:07:45,812 --> 00:07:50,630 independent support for the conclusion. Whereas, in this joint structure, they 108 00:07:50,630 --> 00:07:55,449 work together and they're not going to have force independent of each-other. 109 00:07:55,449 --> 00:08:00,331 It's like the joint in your leg, which joins together the calf with the thigh. 110 00:08:00,331 --> 00:08:03,819 And, if you didn't have both, it wouldn't work very well. 111 00:08:03,819 --> 00:08:06,418 So, we're going to call it a joint structure. 112 00:08:06,418 --> 00:08:10,966 Here's an example. For my birthday, my wife always gives me 113 00:08:10,966 --> 00:08:16,197 either a sweater or a board game. This box does not contain a sweater. So, 114 00:08:16,197 --> 00:08:20,080 this time she must have given me a board game. 115 00:08:20,080 --> 00:08:24,747 Now, notice that the argent marker, so, indicates that the conclusion is, this 116 00:08:24,747 --> 00:08:28,793 time she must've given me a board game. And it's got two premises. 117 00:08:28,793 --> 00:08:33,461 And you might think that they got a linear structure, and the argument goes 118 00:08:33,461 --> 00:08:37,257 something like this. My wife always gives me either a sweater 119 00:08:37,257 --> 00:08:40,556 or board games. Therefore, this box does not contain a 120 00:08:40,556 --> 00:08:43,419 sweater. Therefore, this time she gave me board 121 00:08:43,419 --> 00:08:45,473 game. That doesn't make any sense, 122 00:08:45,473 --> 00:08:48,398 right? I mean, the fact that she always gives me 123 00:08:48,398 --> 00:08:52,879 either a sweater or board game is no reason to believe this box doesn't 124 00:08:52,879 --> 00:08:55,682 contain a sweater. Well, okay. 125 00:08:55,682 --> 00:08:59,749 Let's try it again. Maybe it's a branching structure. 126 00:08:59,749 --> 00:09:04,060 That would mean that the argument looks like this. 127 00:09:04,060 --> 00:09:08,238 My wife always gives me either a sweater or a board game. 128 00:09:08,238 --> 00:09:11,538 Therefore, this time she gave me a board game. 129 00:09:11,538 --> 00:09:16,890 And, as a separate argument, this box does not contain a sweater, therefore 130 00:09:16,890 --> 00:09:19,365 this time she must have given me a board game. 131 00:09:19,365 --> 00:09:23,131 Neither of those arguments makes any sense so it can't be a branching 132 00:09:23,131 --> 00:09:26,537 structure. Instead, what we have here is the two 133 00:09:26,537 --> 00:09:31,806 premises working together. She always gives me either a sweater or a 134 00:09:31,806 --> 00:09:35,526 board game. And, the second premise, this box does 135 00:09:35,526 --> 00:09:40,408 not contain a sweater. Those two premises have to work together. 136 00:09:40,408 --> 00:09:46,375 It's only jointly working together that they can support the conclusion that, 137 00:09:46,375 --> 00:09:49,940 this time she must have given me a board game. 138 00:09:49,940 --> 00:09:56,536 How can we diagram this joint structure? We can put a plus sign between premise 139 00:09:56,536 --> 00:10:01,446 one and premise two, then draw a line under them to show that they work 140 00:10:01,446 --> 00:10:05,387 together jointly. And take a line from that line and draw 141 00:10:05,387 --> 00:10:09,787 an arrow down to the conclusion, just like in the diagram. 142 00:10:09,787 --> 00:10:13,475 And this is what we're going to call the joint structure. 143 00:10:13,475 --> 00:10:18,392 So, we've seen the linear structure, the branching structure, and the joint 144 00:10:18,392 --> 00:10:21,533 structure. And, we can combine more than one of 145 00:10:21,533 --> 00:10:26,860 these structures into a single argument. To see how to do this, let's just do a 146 00:10:26,860 --> 00:10:32,460 slight variation on the previous example. My wife always gives me either a sweater 147 00:10:32,460 --> 00:10:36,079 or a board game. This is box is not contain a sweater 148 00:10:36,079 --> 00:10:41,900 because it rattles when I shake it. So, this time she must have given me a 149 00:10:41,900 --> 00:10:46,683 board game. This argument combines a linear structure 150 00:10:46,683 --> 00:10:51,161 with a joint structure. There are two argument markers. 151 00:10:51,161 --> 00:10:56,494 One is a conclusion marker, so, and that indicates that the eventual conclusion is 152 00:10:56,494 --> 00:10:59,457 that she must given me a board game this time. 153 00:10:59,457 --> 00:11:04,528 But there's also that new word, because, which indicates that the fact that it 154 00:11:04,528 --> 00:11:07,886 rattles when I shake means that it's not a sweater. 155 00:11:07,886 --> 00:11:12,363 So, the first stage of the argument in standard form looks like this. 156 00:11:12,363 --> 00:11:15,326 Premise one, this box rattles when I shake it. 157 00:11:15,326 --> 00:11:19,480 Therefore, conclusion, this box does not contain a sweater. 158 00:11:19,480 --> 00:11:26,531 Stage two says, this box does not contain a sweater, my wife always gives me either 159 00:11:26,531 --> 00:11:32,378 a sweater or a board game. So, the conclusion, this time, she must have 160 00:11:32,378 --> 00:11:36,912 given me a board game. And, of course, the conclusion of that 161 00:11:36,912 --> 00:11:42,698 first little argument is identical with the premise of the second argument, so we 162 00:11:42,698 --> 00:11:47,698 can put them together into a chain. We can say," this box rattles when I 163 00:11:47,698 --> 00:11:52,555 shake it, so it must not contain a sweater." My wife always gives me a 164 00:11:52,555 --> 00:11:57,770 sweater or a board game, so this time she must have given me a board game. 165 00:11:57,770 --> 00:12:02,990 That's how we get a linear structure combined with a joint structure. 166 00:12:02,990 --> 00:12:08,599 And we can use our diagram methods to diagram this argument the same way we did 167 00:12:08,599 --> 00:12:11,660 before. We simply start with premise one, 168 00:12:11,660 --> 00:12:17,033 the box rattles when I shake it. Draw an arrow down to its conclusion. 169 00:12:17,033 --> 00:12:20,304 Namely, the box does not contain a sweater. 170 00:12:20,304 --> 00:12:24,276 That's two. An then, we show that those are joint by 171 00:12:24,276 --> 00:12:29,572 adding a plus, premise three. Namely, my wife always gives me either a 172 00:12:29,572 --> 00:12:34,634 sweater or a board game. Draw a line under them and an arrow from 173 00:12:34,634 --> 00:12:38,606 those two together down to the eventual conclusion, 174 00:12:38,606 --> 00:12:43,440 namely, four that this time she must have given me a board game. 175 00:12:43,440 --> 00:12:48,780 The fact that the top arrow goes from premise one to two, but does not go from 176 00:12:48,780 --> 00:12:54,462 premise one to three indicates that, that premises is a reason for two but is not a 177 00:12:54,462 --> 00:12:58,296 reason for three. So when you use this method to diagram 178 00:12:58,296 --> 00:13:03,637 arguments, you have to be careful where you draw the arrows. And draw them only 179 00:13:03,637 --> 00:13:06,649 where there really is a rational connection. 180 00:13:06,649 --> 00:13:11,099 That is, where one claim is being presenting as a reason for that 181 00:13:11,099 --> 00:13:14,660 particular claim that the arrow is pointing towards. 182 00:13:14,660 --> 00:13:19,280 Now, almost all arguments can be diagrammed using these three simple 183 00:13:19,280 --> 00:13:21,997 structures. That is, the linear structure, 184 00:13:21,997 --> 00:13:24,987 the branching structure, the joint structure, 185 00:13:24,987 --> 00:13:30,286 and some combination of those three. You can add more premises because you can 186 00:13:30,286 --> 00:13:35,721 always add one plus two plus three plus four if they're four premises operating 187 00:13:35,721 --> 00:13:40,869 together in a joint structure. And, you can add extra arrows if you have 188 00:13:40,869 --> 00:13:46,405 a branch with more than two branches. So, you can cover a lot of arguments 189 00:13:46,405 --> 00:13:50,896 using these kinds of diagrams. The method can be described in general, 190 00:13:50,896 --> 00:13:53,907 like this. You start by identifying the premises and 191 00:13:53,907 --> 00:13:58,339 the conclusions, and you number them. So that you can just have numbers instead 192 00:13:58,339 --> 00:14:01,578 of having to write out the whole sentence on the diagram. 193 00:14:01,578 --> 00:14:06,010 Then, when they work together, you put a plus sign between them and draw a line 194 00:14:06,010 --> 00:14:08,908 under it to indicate that they're working together. 195 00:14:08,908 --> 00:14:13,928 They're functioning as a group. Then, you draw an arrow from the claims 196 00:14:13,928 --> 00:14:18,690 that are reasons to the claims that they are reasons for. 197 00:14:18,690 --> 00:14:23,458 And then, you move them around on the diagram so that they'll form a line when 198 00:14:23,458 --> 00:14:28,410 it's a linear structure and branches when it's a branching structure. But, it will 199 00:14:28,410 --> 00:14:33,179 be easy to rearrange them so as to show how all of the different premises and 200 00:14:33,179 --> 00:14:36,970 conclusions work together in a single argumentative structure. 201 00:14:36,970 --> 00:14:42,347 That's going to be enough to accomplish this stage of reconstruction. 202 00:14:42,347 --> 00:14:48,270 Namely, to organize the parts and show how they work together in the overall 203 00:14:48,270 --> 00:14:48,972 argument.