The major themes of "On Another's Sorrow" by William Blake include God's love, faith, compassion, and empathy. The poem portrays God as a benevolent being who empathizes with human suffering and desires to alleviate it. It emphasizes the need for human faith in God's understanding and caring nature, while also highlighting the importance of compassion and empathy among people, as they feel and share the sorrows of others. This compassion should lead to actions that help alleviate the sufferings of others.

The main theme of William Blake's poem "The Little Black Boy" is the equality of all people as children of God, regardless of skin color. The poem emphasizes that physical differences are transient, with true value residing in the soul. It conveys the innocence of the child narrator who is unaware of the full impact of racism, reflecting Blake's condemnation of slavery and belief in the equality of black and white souls.

William Blake used symbolism in his poems "The Lamb" and "The Tiger" in order to contrast two different aspects of the human experience and of God's creation. While the lamb symbolizes the purity, goodness, and innocence of the world before the fall from grace in Eden, the tiger symbolizes the danger, mystery, and fearsomeness of the world after humanity was banished from paradise.

Anger is a significant theme in some poems of William Blake's Songs of Experience, but it is not predominant throughout the collection. For instance, "The Chimney Sweeper" expresses anger toward institutional structures that perpetuate poverty. However, other poems like "The Tyger" focus on awe and wonder, exploring the duality of creation rather than anger. Thus, while anger is present, it is not the universal tone of the entire collection.