Final answer:
Tools are symbols of St. Joseph because they represent his carpentry trade and allude to Christ's Passion in religious iconography, a hallmark of Northern Renaissance art.
Step-by-step explanation:
Tools are symbols of St. Joseph primarily because he was known as a carpenter by trade. In religious art, tools not only represent his profession but also symbolize deeper spiritual meanings. As is common in Northern Renaissance art, these tools reference the Passion of Christ. Similarly, saints are often depicted with icons or items that are associated with their martyrdom or their roles in scripture, thus serving to identify them and illustrate their lives or deaths. As for St. Joseph, the depiction of his tools in art, links to the labor and suffering of Jesus, foreshadowing his crucifixion and redemptive sacrifice. Other examples include Saint Catherine with her wheel and Saint Sebastian with his arrows. This blending of the material and spiritual is a hallmark of religious iconography, attributing sacred meaning to everyday items.