Confidence is a static state. Determination is active. Determination allows for doubt and for humility - both of which are critical in the world today. There is so much that we don't know, and so much that we know we don't know. To be overly confident or without doubt seems silly to me. Determination, on the other hand, is a commitment to win, a commitment to fight the good fight.
Letters to a Young Artist (ed. Anchor, 2008) - ISBN: 9780307487445