are five questions, two basic ones and then three follow-ups, which
people with an aptitude for philosophy tend to give the same (correct!)
answer to. It is not an intelligence test or any kind of general or
specific knowledge test. In fact, it is not really a test but a vague
Here are the questions. First the two core questions, and answers to them after a peek-frustrating gap.
(A) If the word "ostrich" (in a possible language) meant what "zebra"
actually means in English, and "zebra" meant what "ostrich" means, how
many legs would an ostrich have? [I gather this is a medieval puzzle.]
Russell is said to have told a (sexist?) joke. He met someone who was a
convinced solipsist. That is, she thought that she was the only mind in
the universe, because the evidence that other bodies hosted minds was
inadequate. But she had one puzzle, why didn't everyone else think the
same? The question is: why is this a joke?
down your answers to these questions. (If you do not, then when you see
my answers you may – probably will – persuade yourself that that is
what you meant. This takes away the point.)
Answers to (A) and (B)
would have two legs. The question and this answer are in English rather
than some possible language, and what something is called does not
change how many legs it has.
It is a joke because the solipsist shows by her reflection/question
that she does after all really think that there are other minds.
(Because otherwise why would she wonder about what they thought?)
Now the follow-ups to these two answers.
(F2) What can be said in defence of the opposite answer to the ostrich question?
some ways that it is a bad joke, that is, ways that the
question why others do not think the same is not really so silly.
(F3) what do the two questions (A1 and B1) have in common?
A small gap now, and then comments on these follow-ups.
(F1) Ostrich follow-up: as normally understood (rather than as taken in a
dogmatically hyper-literal way) the question might be understood
differently. It might not be really "how many legs would an ostrich
have?" but "what claims expressed as 'an ostrich has n legs' would be
true?". (Do you see why these are different?) And if "it would be true"
means true in that possible language, then since "an ostrich has four
legs" would be true, the answer is four. (n=4, in the ponderous
Or or one might appeal to the fact that millions of people worldwide
speak several languages regularly and often switch between them in the middle of
a conversation. So taking the question and the answer in the possible
language is not that perverse.
Solipsism follow-up: several possible ways in which the question might
be not a silly one, even for the solipsist Russell described in the joke. (i) people do in fact question whether solipsism is
true. (The majority of philosophers think it is false.) So the question
could be how this can be true, assuming that in fact it is true. (ii) the
person asking the question might be admitting that they sometimes doubt
solipsism, and wondering how this can be. (iii) different parts of a
single mind might not have access to other parts, so that any given
part might either believe or doubt that the others exist. [Follow-up to
the follow-up: what is the difference between separate parts of the
same mind and separate minds? See how questions multiply.]
the two questions have in common: (i) in both of them an answer that in a way is
obvious can seem difficult. (And the obvious way of understanding and
answering it might seem shallow, if one is looking for philosophical
depth, though sticking to what is clearly true and avoiding
illusory depth is much more difficult than it seems at first.) (ii)
the ostrich question understood in the follow-up way requires one to
think so as to acknowledge the possibility of another mind speaking a
different language where the same facts are expressed in different
words. (iii) the possibility of different languages with the same words
referring to different things presupposes a possible plurality of minds. (iv) both of them involve running together
two points of view, in the ostrich question and actual and possible
language and in the solipsism question a locked-in-subjectivity
standpoint and a normally social standpoint (All the same, the first
set of answers are the best ones, those that have fewest problems, and they are the natural replies to the questions as
(The first answers and the many potentially complicated
further answers remind me of a saying that I associate with Paul
Benacerraf "in philosophy you never really solve a problem; you just
establish its price". If you insist on believing something there are
other things you must also believe and other things that you must
abandon. Those are its price.)