Edward Winkleman has an interesting post on his blog  "What Makes Someone "Not an Artist?”. For myself the answer is very simple. There is no such thing as a "non artist".  Here's a quote from his site.

                       "We have degrees and exams to define doctors or lawyers or scientists and such, but even armed with an MFA, a graduate seemingly still needs to pass some unspoken test to earn the title "artist" for most people. And of course, there's no requirement that one has an art degree to earn the title if the evidence (their art) is convincing enough. We would never  let a self‑taught "surgeon" demonstrate their right to that title (at least, not on us) or a self‑declared "lawyer" try an important case for us, no matter how many episodes of "Law & Order" they convinced us were decided incorrectly. As a society, we have measures of competence for such professions we expect to be met.

    This seems to be such a hard question to get a straight answer to.  Occupations such as lawyers and doctors are highly specialized niches where as art  is a universal human experience.  Long before there were lawyers and doctors there were cave paintings in France and although the concept of "Art" may not have existed for the people who drew the pictures of animals and hunters on the cave walls who in our modern world would argue that it's not art.

    One definition often used to define an Artist is the creation of some object or idea from scratch.  What's often over looked here is that this creation is going on all the time all around us.  All of human existence is an act of creation.  We are born, experiences happen to use and over time we weave those experiences into a narrative that tells the stories which are our lives.  These individual stories entwine to form communities and these communal stories entwine to form our collective history.  All of human civilization is one big art project.  It is such a universal experience that almost everyone thinks nothing of it.  Even people who title themselves Artist may be blind to the fact that their  everyday experiences are  acts of artistic creation.  The reason why it's so hard to define an Artist is because every human has a right to claim that title for themselves if they want it.

    In today's culture a capital A "Artist" would usually be  regarded as a specialist.  They choose their materials, their mediums and their subjects.  They develop their specialized symbolic vocabulary and hopefully their fellow human beings will place some value on their creations.  With some luck these individual acts of creation will get added to the larger human art project of civilization.