This particular heresy is one that really bugs me because of how prevalent it is. If you can doubt the clear saying of Scripture here, where else are you allowed to fill in your own meaning?
Symbolism is a term to describe the protestant Eucharistic heresy taught by the Arminians, Calvinists, and Radical Reformed. Their teaching is that the bread and wine simple “represent” or “symbolize” the Body and Blood of Our Lord. This teaching was resoundingly rejected by Martin Luther at the Marburg Colloquy with Zwingli, and is also condemned by the Catholic Church.