The first spectators of Shakespeare were probably more receptive than we are. We tend to take art less seriously than they did. For modern man the supreme distinction is between 'fiction' and 'truth', as we say, between art on the one hand and 'reality' on the other. Now naturally our medieval ancestors made the same distinction, but for them it was not so sharp. They were not in the habit of speaking and thinking of life as 'truth'. By truth, by reality, they meant something different; for them the supreme distinction was not between life and art, but between the next world, that is, Truth, and this world, which is the shadow of Truth. The sharpness of that distinction took the edge off all other distinctions.
Moreover, art for them was not merely a copy of life, that is, it was not merely the shadow of a shadow; it was also by inspiration, partly -- and in some supreme cases even almost wholly -- a direct copy or shadow of the 'substance' itself. The distinction between art and life is therefore no so much between a shadow and a reality as between two shadows.... By attributing a less absolute reality to life they attributed more reality to art. They no doubt entered into it more whole-heartedly. ~Martin Lings, "The Secret of Shakespeare" (emphasis mine)