Final answer:
Sydney Carton has a negative opinion of himself, seeing his life as wasted despite his intelligence, which contrasts with his redemptive self-sacrifice by the end.
Step-by-step explanation:
Sydney Carton's opinion of himself is notably negative throughout much of Charles Dickens' novel A Tale of Two Cities. Carton sees himself as a wasted man; he's acutely aware of his squandered potential and his lack of ambition, which leads him to live a life of dissipation.
Despite his intelligence and capability, particularly displayed in his legal work, Carton's self-loathing is profound, and he considers himself far from heroic or worthy of happiness.
This outlook is sharply contrasted by the self-sacrificial act he ultimately carries out, which embodies a greater sense of self-worth and redemption.