So far we've been discussing ad hominem 
arguments, deniers, silencers, and 
dismissers. 
And as I've said, many ad hominem 
arguments are guilty of a fallacy of 
relevance. 
The premises are not relevant to the 
conclusion. 
Now I'd like to describe a different kind 
of argument, 
an argument that I call an appeal to 
authority. 
And many arguments of this second kind 
are also guilty of fallacies of 
relevance. 
Now appeals to authority, 
like ad hominem arguments, start from 
premises about a particular person, a 
person who is making a certain point or 
defending a certain conclusion and they 
move from premesis about that person to a 
conclusion that's about the point that 
person is making So in the respect that I 
just mentioned appeals to authority are 
just like ad hominem arguments. 
But there's one important difference. 
Whereas ad hominem arguments, draw a 
negative conclusion, about the point that 
some person is making, appeals to 
authority draw a positive conclusion 
about the point that person is making. 
So just as there are three different 
kinds of ad hominem arguments, deniers, 
silencers, and dismissers, so to there 
are three different kinds of appeals to 
authority and I'm going to call them 
[SOUND] 
affirmers, 
[SOUND] 
amplifiers, and supporters. 
Now lets consider each one of these types 
in turn. 
Let's start by talking about affirmers. 
Affirmers, recall, are the opposite of 
denier ad hominem arguments. 
In the denier ad hominem argument, we 
start with premises about a person who's 
making a certain point, and we move to 
the conclusion that the point that that 
person is making is false, or probably 
false. 
In an affirmer appeal to authority 
argument, we once again, start with 
premises about a particular person, but 
then we move to the conclusion that the 
point that the person is making is true 
or anyhow, likely to be true. 
Let me give you an example of an affirmer 
appeal to authority. 
Suppose I said you write now, I'm talking 
to you. 
Now you might reason as follows. Rom said 
that he was talking to me, therefore he 
was talking to me. 
So you start with a premise about me, 
about what it is that I said. 
In this case I said that I was talking to 
you and then you move from that premise 
to the conclusion that I was talking to 
you. 
Now notice in this case the conclusion 
that you arrive at is the conclusion that 
what I've said is true. 
Because what I said just that I'm talking 
to you and your conclusion is that I'm 
talking to you. 
So your conclusion is just the acceptance 
of the truth of what I've said. 
Now why do you accept your conclusion? 
Well because I said that I was talking to 
you. 
But you see, I coudn't have said to you 
that I was talking to you unless I was 
talking to you. 
So this is a case of an affirmer appeal 
to authority, 
an argument where you start with a 
premise about me, and you move to a 
conclusion, to the effect that the point 
I was making was true. 
It's an affirmer appeal to authority 
that's justified. 
The argument that you just made is a good 
argument. 
If I did say to you, that I'm talking to 
you, then it's true. 
That I'm talking to you. 
So this is a case of a justified affirmer 
appealed to authority. 
But there are also cases of unjustified 
affirmer appeals to authority. 
Now let me give an example of an 
unjustified affirmer appeal to authority. 
Suppose I say to you now, Je parle 
Francais tres bien. 
Now in French that means I speak French 
very well. 
Now if I say that to you right now, you 
might conclude that I do speak French 
very well. 
Because I just said, Je parle Francais 
tres bien. 
But that would be a mistake, and it's not 
just a mistake because I don't speak 
French very well, it's also a fallacious 
inference, because when I say in my poor 
broken French, Je parle Francais tres 
bien, I'm not giving you very good 
evidence that I do speak French very 
well. 
So for you to conclude on the basis of 
what I've said, that I speak French very 
well, would be for you to draw an 
unjustified conclusion. 
So that's an example of an affirmer 
appeal to authority that is unjustified. 
Now let me talk about amplifiers. 
An amplifier is an appeal to authority in 
which we move from a premise about a 
particular person who is making a point 
to the conclusion that their point is one 
that we should pay special attention to. 
We should lend special credence to the 
point they're making. 
Now, some affirmers are justified. 
So, for instance, suppose we're trying to 
figure out whether a player in some game, 
is guilty or not of a foul, and the 
referee declares the player guilty of a 
foul Now, you might reason that since the 
referee said that the player was guilty 
of a foul, that means the player is 
guilty of a foul. 
What you're doing there, is reasoning 
from the fact that the referee said it to 
the truth of what the referee said. 
But the reason why you assign importance 
to the fact that the referee said it is 
because in most games the referee gets to 
decide if the person is guilty of a foul 
or not. 
Whatever the referee decides is taken as 
truth. 
So there the referee is in a special 
position to decide what's true. 
In contrast to other people, who might 
have opinions about what's true, but have 
no authority to decide the matter. 
Now in that case, where you infer from 
the fact the referee said the player's 
guilty of the foul, (no period) To the 
conclusion that the player is guilty of a 
foul, you make an appeal to authority 
that in general is justified. 
That's an example of a justified 
amplifier argument. 
But there are also amplifier arguments 
that are unjustified. 
For instance, suppose that the tallest 
player on the field, declared, that some 
other player was guilty of a foul. 
Well you might infer that since the 
tallest player on the field says that 
this other player was guilty of a foul, 
the oth, other player is guilty of a 
foul. 
But that would be a mistake. 
Just because the tallest player on the 
field said so, doesn't mean that they 
have any special voice in the matter. 
And special role in determining, whether 
or not the other player is guilty of a 
foul. 
So amplifier arguments, just like 
silencer arguments, can be justfied, or 
unjustified. 
And when they're unjustified, they're 
guilty, of a fallacy of relevance. 
Finally, I want to talk about, supporter 
appeals to authority. 
In the supporter appeal to authority, you 
move from a premise about a particular 
person who is making a point to the 
conclusion that the point they're making 
is one that you have additional reason to 
believe. 
So it's the opposite of a dismisser ad 
hominem argument. 
In a dismisser ad hominem argument, you 
move from a premise about a person making 
a particular point to the conclusion that 
their point is one that you have no 
special reason to believe. 
Finally let's talk about supporter 
appeals to authority. 
In the supporter appeal to authority you 
move from a premise about a person who's 
making a particular point, to conclusion 
that the point they are making is worthy 
of belief, is likely to be true. 
So, let's consider an example of a 
supporter appeal to authority. 
The intergovernmental panel on climate 
change has said that over the last 
century, the temperature of the Earth has 
gone up by 1 degree Celsius. 
Now do you believe that? I do. 
And I believe it because. 
I believe that the Intergovernmental 
Panel on Climate Change represent the 
best effort of a whole lot of experts 
about climate. 
So, because there's a lot of expertise 
that goes into the IPCC's information I 
accept the conclusion that they come to. 
The fact that they say it, lends that 
conclusion a great deal of creadence in 
my mind because they're experts. 
That's an example of a supporter appeal 
to authority. 
That I take it, is justified. 
But lets compare that to a supporter 
appeal to authority that is unjustified. 
Suppose that a magician performs at the 
IPCC panel on climate change, and in the 
course of the magician's performance, the 
magician pulls a rabbit out of a hat, 
well everyone in the audience is 
astonished doesn't understand how this 
magician could possibly have pulled a 
rabbit out of a hat. 
And the magician says to them, it's 
magic, and look, I've just prove to you 
that magic exists. 
Well suppose the magician was able to 
pursuade All of the members of the IPCC, 
that magic exists, because he was just 
able to pull a rabbit out of a hat after 
all. 
And so the IPCC includes in, its report 
on climate change, an appendix about the 
existence of magic. 
Now, I don't know about you, but I would 
not believe what the IPCC has to say 
about the existance of magic. 
It's not that I think that the members of 
the IPCC aren't experts about anything, 
but I don't think that they're experts 
about magic. 
So while I might trust what they say when 
it comes to climate, I don't trust what 
they say when it comes to magic because 
they have no special reliability on the 
topic of magic. 
So, an unjustified support or appeal to 
authority would be an argument that moved 
from some premise about the IPCC, to a 
conclusion that we have special reason to 
believe the IPCC when it says that magic 
exists. 
Just because the IPCC consists of a bunch 
of experts on climate doesn't mean that 
it consists of a bunch of experts on 
magic. 
And so, any support or appeal to 
authority that tried to reinforce the 
IPCC's statement of the existence of 
magic by appeal to the reliabilty of the 
IPCC. 
Would be an unjustified supporter appeal 
to authority. 
So far today we've talked about different 
kinds of ad hominem arguments and 
different kinds of appeals to authority. 
We've distinguished three varieties of 
each of those kinds. 
And we've distinguish between the 
justified and the unjustified versions of 
each of those varieties. But what we find 
in every day life is that we frequently 
encounter dismisser ad hominem arguments 
and supporter appeals to authority and We 
need to choose between these. 
We're in a situation where we need to 
decide whether or not a particular 
dissmissor ad hominem argument is any 
good or a particular supporter appeal to 
authority is any good. 
And those are the situations that this 
course should be aimed to address. 
So next time I'm going to discuss those 
situations in more detail. 
And with more examples. 
Also I should mention, all of the 
examples that we've considered today of 
ad hominem arguments or appeals to 
authority were examples where what was at 
issue was the testimony of a particular 
individual. 
Sometimes it's not individual testimony 
that we're considering. 
Sometimes the point that we're asking 
about is a point that's being made by a 
group, or by a tradition, or by a 
culture, or by a government. 
And in those cases as well, we can have 
ad hominem arguments. 
That tried to undermine the authority of 
that group, or that culture, or that 
government, and appeals to authority that 
try to support the authority of that 
group or that culture or that government. 
Next time we'll talk about some examples 
of those also.