Why does the speaker in The Tyger wonder that the creator of the Lamb and the tiger is one and the same? (MEG 102) (Songs of Experience: Study of Some Poems)

In the poem "The Tyger", the speaker is in awe of the beauty, power, and ferocity of the tiger. The poem begins with the speaker asking, "Tyger Tyger, burning bright, / In the forests of the night; / What immortal hand or eye, / Could frame thy fearful symmetry?" The speaker is amazed at how such a powerful and majestic creature could have been created. The speaker then goes on to ask, "Did he who made the Lamb make thee?" The speaker is puzzled by the fact that the same creator could have made such different creatures, one gentle and innocent, the other fierce and powerful. The poem explores the idea of the coexistence of good and evil, and how they are both part of the natural order of things. The tiger is a symbol of the darker side of nature, but it is also a thing of great beauty, and the speaker acknowledges this duality in the final lines of the poem: "And when thy heart began to beat, / What dread hand? & what dread feet? / What the hammer? what the chain? / In what furnace was thy brain? / What the anvil? what dread grasp, / Dare its deadly terrors clasp!"