Seneca acknowledges the balance between human agency and forces beyond our control. We must make thoughtful plans and work diligently toward our goals, but we must also remain flexible when circumstances change our path. This isn't fatalism but practical wisdom - we prepare as best we can while staying open to unexpected opportunities and challenges. The wise person plans carefully but holds those plans lightly, ready to adapt when fortune presents a different course. It's the integration of responsibility and acceptance that creates both effectiveness and peace.