"Gold, and silver, and brass"
Rabbi Shimon opens the discussion with the verse, "And this is the offering which you shall take of them; gold, and silver, and brass." This passage is both toward the upper side, which is the side of holiness or the right side, and the lower side, which is the 'other side' or the 'left side.' When God created the world and the tabernacle, he made them opposite, so that while they are both silver and gold, the world is begun from silver, or right, while the tabernacle is begun from gold, or left.
Good and evil are undeniable forces that live within us. This truth is revealed by way of the metal metaphor (gold, silver, and brass), whose purpose is to help us become truly cognizant of their influence. Our inner aspect of good now emerges as our dominant feature, and we finally uproot and eliminate the evil component forever. As our own negative traits are toppled, the macrocosmic force of evil is conquered in equal measure.