How can we measure the value of Art?

I suppose that if you are on this blog, most probably you like art.

But what is Art? How can we recognize artistry? I do not have any diploma from the Art school, but I have my own opinion about it.
My definition of the value of the artistry is strictly connected with time. For example: if people still want to read some literary works, many years since their creation, this kind of art is valuable. We can be pretty sure that artworks written by legendary geniuses will bring us some new, fresh approach to many things. These classic books will bring us insightful thoughts – in spite of the age of the books.

Similar cases we can find in paintings (Leonardo da Vinci, Salvador Dali), music (David Bowie, Michael Jackson, Jim Morrison) and of course in photography (Henri Cartier-Bresson, Edward Steichen, Alfred Stieglitz, Eugène Atget).

Contemporary people sometimes do not understand the thoughts and ideas of the visionaries who ahead of their time. That is why I think that the real value possesses these artworks, which can be noticed and appreciated by descendants.

That’s why I believe today it’s impossible to say if my photographs are this kind of Art which will last forever. I hope they will.
And for you, my Dear Guest? What makes the real value of artistry for you?