It’s not trivial to explain where this “proof” goes wrong, and anyone who spars with problems like these and learns the art of overcoming them will come quickly to appreciate the curious case of the absolutely flawless reasoning with the completely unacceptable conclusion! Indeed, there is such a thing as savouring a paradox before wrestling with it and this experience is available to anyone who is open to it. Sadly, this fact is often lost upon those who regard paradoxes as nothing but affronts to their intelligence.To prove that there exists a unicorn, it’s enough to prove the stronger proposition that there exists an existing unicorn. (An “existing unicorn” is just a unicorn which exists.)For, obviously, if there exists an existing unicorn, then there must exist a unicorn!So all we have to do is prove that an existing unicorn exists. But that’s not very hard. How could an existing unicorn not exist? That would be a contradiction!