Philosophers are interested in explaining man’s place in the world by developing a coherent and rational
worldview or system of beliefs. This type of worldview differs from other attempts at creating a
comprehensive explanations of man’s place in the world such as mythical or religious explanations because
philosophers insist that the beliefs have to be rationally justifiable. For that purpose philosophers examine
the meaning, logical relations and, truths of fundamental concepts. In this sense philosophers differ from
scientists who also try to explain the world rationally. Scientists typically try to understand observed
regularities in nature by finding the causes that produce them. To this purpose they apply the scientific
method to determine what is causally possible. Philosophers, on the other hand, are interested in the
meaning, logical relationships, and truths of the fundamental concepts in our system of beliefs. Therefore,
philosophers are usually as interested in logical possibility as they are in what’s causally possible. Roughly
speaking, the difference between logical and causal possibility is that what is causally possible is
determined by the laws of nature whereas logical possibility is determined by what you can conceive of
without contradiction; or, to put it differently, what you can imagine coherently. For example, I can imagine
a cow jumping over the moon without any problems, however, I know that this is far from causally or
physically possible because of gravity and the distance involved. On the other, try as I might, I can’t imagine
what a round square is, or a married bachelor: a married bachelor would be a married unmarried man,
which doesn’t make any sense, it’s a contradiction.
Science fiction, as a genre, investigates the borderland between causal and logical possibility by imaging
scenarios where new technologies or beings from other worlds are encountered. In a sense, philosophers
and sciencefiction writers have in common that they are interested in ”What if? Questions. Philosophers
are interested in these imaginary scenarios, or thought experiments, because they can tell us something
about how our concepts apply in new situations. Scientists are also interested in thought experiments but
usually much more interested in facts and real experiments. For example, it’s difficult to see how you can
devise a scientific experiment that will determine whether or not we have a free will without first carefully
analyzing the concepts involved.
One of the most important tools philosophers use is definitions. The types of definitions philosophers use
are slightly different from the ones you typically find in dictionaries. A definition in a dictionary will give you
standard usage of the word and some common synonyms. A philosophical definition is more involved
because it tries to etablish the criteria for how we apply a concept. A definition analyzes a concept by
specifying the conditions under which the concept applies. This is done by writing up a definition in a
standard way that makes it clear what those conditions are. An example we used in class was a definition of
what makes something a work of art. We wrote this up in the following way:
Something is a work of art if and only if :
1. It is a man made object
2. It represents an object found in nature
3. It is beautiful
In an good or adequate definition the conditions listed to the right of the concept you want to define
specifies what is called necessary and sufficient conditions for the application of the concept. A necessary
condition, in our example, is a condition that has to be satisfied in order for something to count as a work
of art, or put differently, something cannot be a work of art unless this minimal condition is satisfied. In
this particular definition the 3 conditions are said to be individually necessary; this means that nothing can
be a work of art unless all 3 of the conditions are satisfied. The conditions taken together specify what is
called a sufficient condition. If something is a sufficient condition it means that if the conditioned is
satisfied, then it guarantees that, in our example, something is a work of art. To illustrate the difference
between a necessay and sufficient condition think about what it means to be a ”a winner of the Powerball
lottery”. A necessary condition for winning is that you buy a ticket because you can’t legitimately win the
lottery unless somebody buys a ticket. Unfortunately, buing a ticket does not guarantee that you will win.
It’s a necessary condition but not a suffcient condition. What, then, is a sufficient condition for winning? In
order to be a winner your ticket has to have the combination of numbers that are actually drawn. Having
the ticket with the winning numbers is a sufficient condition for being a lottery winner. Or, to take another
example, being a dog is a sufficient condition for being an animal because if you know that something is a
dog then you also know that it is an animal. However, being a dog is obviously not a necessary condition for
being an animal since there are many more ways of being an animal, being a cow or a cat for instance.
Therefore, being a dog is not a necessary condition for being an animal. Or, to go back to the lottery
example, winning the Powerball is a sufficient condition for becoming a millionaire, but it is not a necessary
condition since there are other ways of becoming a millionaire.
If the conditions you have specified in your definition are individually necessary and jointly sufficient, then
you have an adequate or acceptable definition. In order to test your definition, that is, to make sure it’s
adequate, try to see if you can come up with a counterexample. If you can think of something that should
be contained within the definition but falls outside it, or something that is excluded by the definition but
should be contained in it, then you have produced a counterexample. For example, can you think of
something that doesn’t satisfy one of the conditions in our definition of what constitutes a work of art? It’s
not very difficult, there are plenty of pictures in museums, that are abstract paintings; so they clearly do
not depict an object in nature, still they are considered to be art. Because of this counterexample we have
established that the definition is inadequate, it is too narrow because it does not allow something to be
part of the concept work of art that should be included. As a matter of fact, the definition is also too wide
because we can think of objects that satisfy all the conditions but we wouldn’t consider works of art. The
pink plastic flamingo on my lawn is man made, I think it’s beautiful, and it does represent something in
nature. But, it would not be considered a work of art.
If we are interested in a world view that is coherent and rational, then we want to make sure that our
system of beliefs are consistent . For two beliefs to be consistent, it has to be possible for them to be true
at the same time, on the other hand, if it’s impossible for them to be true at the same time, then they are
said to be inconsistent. We want to make sure that our beliefs are consistent because if they are
inconsistent, then a certain number of our beliefs must be false. For example, if I believe that everything in
the universe is made of matter of some sort and I also believe that angels exist, then I might hold
inconsistent beliefs. The inconsistency occurs because angels are generally considered to be immaterial or
spiritual substances. If that is the case, then clearly the two beliefs cannot both be true. Notice that in order
to determine whether some of our beliefs are consistent or not, we are forced to examine the concepts
we employ. It depends on how we define what an angel is whether or not the two statements are
inconsistent. Maybe you can define angels as being made out of some sort of matter that makes their
existence compatible with materialism (the view that everything is made of matter). Because consistency
sometimes depend on how you define your concepts, it sometimes requires an explanation to determine
when a set of statements or beliefs are consistent or inconsistent.