Symbolism in Art
Artists have long used symbols to carry a message, an idea, an emotion, or a story. The message is not obvious to every viewer, especially in an old picture whose signs were plain to its first audience and opaque to a later one. Meaning also shifts with the viewer's culture. Color has changed its reading over time. Animals are not the same animal in every tradition. A picture can be taken however one likes. For a viewer who wants the story the painter had in mind, the way in is the artist, the period, the culture, and the meaning those signs had then. One painter's use of them is followed on the Gauguin page. A few signs recur often enough to name on their own.
The apple
The apple is a common subject in classical and modern pictures. In Christian tradition it is the fruit of the forbidden tree, the one Adam and Eve ate after the serpent's temptation. For a later, technical culture the same fruit became the mark of a company, which is a different proposition entirely.
The lotus
A picture of Lakshmi does not go very deep if the viewer does not know what the lotus means in Hinduism. The flower is how her wisdom is shown. She remains unspoiled as goddess of wealth, just as the lotus stays clean in the mud it grows from.
Blue
Painters almost always put the Virgin Mary in blue. Blue has stood for truth and for clarity, and it is the color of the sky, read as heaven, which is where she belongs as the mother of God. A wider account of hues is on the colors page.
The lion
In the Hebrew Bible and across the ancient Near East, lions stand for monarchs. In the story of Daniel, he is thrown into a den of lions for praying to his God after King Darius has ordered that, for thirty days, prayers go to the king alone. Daniel comes out unharmed. The lions around him have been read as the empires and nations of the world, set around Israel.
The triangle
Religious art takes the triangle as the Trinity. In pagan reading, a triangle pointing up is a sword or fire, and masculine. A triangle pointing down is a chalice or water, and feminine. Those two directions are also the alchemical signs of fire and water on the four elements page.