Each card has one capital letter (e.g. F, G, X etc.) on one side, and one number (below 10, e.g. 3, 7, 8 etc.) on the other side.

At the moment, the cards show K, -4, 7, P, R, 0, 5, and 2.

What are the cards you really need to turn over to determine whether or not it's true of all the cards on the table that if there is a vowel on one side, then there is an even number on the other side.

There is no trick. I'm just asking to have your opinion.

Take your...

Eight cards are on the table.]]>

Second, if you think it is not a paradox, please explain briefly why.

Finally, do you think it should be possible to prove there is in fact no paradox.

Thank you to stick to the...

The Liar's paradox]]>

Either way, why?

EB]]>

It is designed to help people understand modal logic and for some to stop the red herring of the so-called "

You can all vote, not just Sarkus.

Here is the argument:

Thank you to vote before posting any comment.

EB]]>

EB]]>

Thank you to vote before posting any comment on the argument (you can change your vote if need be).

Here is the logical argument:

For all we know, A may be the state of some unknown part of B;

C is determined by the state of some unknown part of B;

Therefore, for all we know, C may be determined by A

C is determined by the state of some unknown part of B;

Therefore, for all we know, C may be determined by A

Is the argument valid?

EB]]>

First example, dictionary definitions. Dictionary definitions are empirical evidence of how words are used and of what they mean.

So, to know what the word “empirical” means, we can look at the empirical evidence provided by a dictionary definition of what the word “empirical” means:

A king summons three of the wisest men known in his realm, and tells them he wants to test their wisdom.

He explains they will be led to a room in which they must sit in a circle facing inward.

He then tells the three that each of them will be blindfolded and a hat placed on their head.

Each hat can be only white or red. After removal of the blindfolds, the first of the three to say what color hat he is wearing will be ruled the wisest.

At this point the king...

The three wise men problem]]>

Thank you to vote before posting any comment on the argument (you can change your vote if need be).

Here is the logical argument:

For all we know, A may be the state of B;

What C does is determined by the state of B;

Therefore, for all we know, what C does may be determined by A.

What C does is determined by the state of B;

Therefore, for all we know, what C does may be determined by A.

Is the argument valid?

EB]]>

Formal structure of a logical argument]]>

But it needs not be tested by repetition. We can predict a phenomenon and see what happens when we set to prove it.

If we ask the universe about a non-selfevident aspect and we ask it nicely (in proper mathematical terms) the universe will provide the answer.

This is how we managed to have the universe reveal the Higgs...

Reality is mathematics / Mathematics is reality ?]]>

Mathematicians who worked on the conception of a method of logic in the 19th century, Frege in particular, were essentially and explicitly motivated by the idea that a proper method of formal logic would help improve the rigour of mathematical proofs, a particular concern at the time, between the two extremes of Abel and Weierstrass. This suggests a view of logic as essentially...

Logic: empirical or abstract science?]]>

As a motivation introduction, I observe that most educated people take logic to be a branch of mathematics, or perhaps whatever mathematicians study that they call "logic" since broadly the beginning of the 20th century. Yet, the first systematic presentation of what humans understand of logical rules was made by Aristotle and that was something like 2,400 years ago, and as far as I know, most intellectuals since have accepted...

Whence comes logic]]>

Or perhaps less metaphysically, there doesn't seem to be any conceivable logical case or situation in which we would assess the expression as being false.

Now, the mere

Criteria of validity in empirical sciences]]>

Thanks.

EB]]>