Transcript for:
Organizing Categorical Syllogisms

Once we get comfortable with categorical  syllogisms laid out in their scientific logical   way, we need to figure out how to deal with  arguments that aren't laid out in this organized   manner. And with that in mind, we'll move into a  three-step process. So step one, we're going to   use our indicators to identify our conclusion  and put our conclusion at the bottom line. So   that's your goal right out the gate is to put your  conclusion at the very bottom of your argument.   And then step two, you're going to remember that  the subject of your conclusion is your minor term   and the predicate of your conclusion is your  major term. And then step three, based on that   information in step two, we're going to find our  premise with the major term and we're going to put   it in the top and make that our major premise.  And then we're going to find our premise with   the minor term and put that in the bottom and make  that our minor premise. So then we'll have major   premise, minor premise conclusion. Here's what  that looks like. So with this example, we have no   silicates or crystalline substances because all  silicates are oxygen compounds and some oxygen   compounds are not crystalline substances. I have  no idea what any of this means but that doesn't   matter, because all I'm trying to do right now  is organize it into standard form. An argument   that was already organized in a standard form  would have the conclusion at the bottom, but I'm   not sure if the conclusion is at the bottom here.  So what I'm going to do is I'm going to look for   my indicators. I'm gonna try and find conclusion  and premise indicators and see if I can't set the   premises and the conclusion according to that. No  silicates are crystalline substances because. Okay   because is an indicator. It's not a conclusion  indicator, but I'm gonna mark it right now. Still   looking for conclusion indicators. That's the best  bet. All silicates are oxygen compounds and some   oxygen compounds are not crystalline substances.  Okay, all I see in here is the premise indicator   “because,” but there's something else that's going  to help me in this argument. And that's the word   “and.” And tells me we have a continuation of  thought, so more of the same and so we know with   this premise indicator that what's coming up next  is our premise. And tells us more of the same,   so what's coming up here is another premise.  So we have all silicates or oxygen compounds,   some oxygen compounds are not crystalline  substances. Those are our premises. The problem   is I'm not going to know which premise goes where  until I have my conclusion sorted out and the   parts of it identified. So I'm going to leave  the premises alone and go to the conclusion. No   silicates are crystalline substances and put that  at the bottom. So we're gonna replace silicates   with S crystalline substances with C and so at  the bottom of our argument we're gonna write the   conclusion no S are C. Now it's time for the work  to sort out what premise goes where. We know S is   our minor term of the conclusion because it's in  the subject position of the conclusion, so that's   our minor term. And that minor term is going to  go in the bottom or second premise. This C is the   predicate of the conclusion; the predicate of the  conclusion is called our major term and whatever   has the major term in it is going to go in the  top or first premise. So now we just go back and   look at our premises, find which premise has the S  in it, that's going to go in the second location.   Find which premise has the C in it, and that's  going to go in the first location. Returning   to our premises we see all silicates are oxygen  compounds, so that's going to be all S are 0. And   the S is the minor term and so this is going to be  called the minor premise. It's going in the second   position, so we're gonna go all S are O because  once again it has the S in it and there's the S   from the conclusion. The subject of the conclusion  which makes it the minor term. Now just to double   check our work, I assume that the other premise is  going to go up top but just to be sure we're gonna   be sure that that C of our major term occurs  in this second premise of our argument. So it   says some oxygen compounds are not crystalline  substances. I'm going to rewrite that as some   oxygen compounds O are not C for crystalline  substances, and sure enough yeah there's the   C of our major term. It does happen in this second  premise so we're going to move that premise to the   top location and write some O are not C. For bonus  points do we remember what this O term is referred   to as? I'll tell you the answer in three two one  go: it's the middle term. So we have the major   term with the C that occurs in the top premise,  we have the minor term the S that occurs in the   bottom premise, and we have our middle term  which is repeated in both premises. And now   our argument is set up for formal scientific  logical analysis. And so what we've done here   is converted a non-standard form argument into  standard form I hope this helps. Take care bye.