What is Art? Hmmm big question this time! Art is subjective, so, this answer has to be subjective too, my opinion on art is not necessarily another artist's opinion. So, where to start, well the beginning is a tad hard to find, the Lascaux hand paintings were our ancestor's way of enrich their environment. This is, of course, an educated guess. What I would want to do in a place that did not have an interpretation of my feelings and inspirations? I would try and find a way to create an external representation of these feelings.
Humans have always changed their environment and not always for the best, but some of us do want to leave a lasting impression of a positive interaction. Are the hand print and animal drawings maybe a trophy, a diary of what they did that day, a representation of the animal for their ability to survive another day? Unless we were there the answer is subjective and we can only go with our own feelings.
The experiences we all have while getting to this point in time defines who and what we are and therefore defines what we create with our artistic personality. So in the Upper Paleolithic era (17,300 years ago), the artist would have a vastly different number of experiences to the artists of the day.
Some of the paintings are hidden away in caves which makes me wonder if the artists were hiding their talent in case of prejudice. In a society where finding food and surviving day to day was so important, would it have been seen as a waste of time and energy creating such beautiful work? Why would our ancestors be any different than us and we are full of prejudges.