optimism (n.)

• blitheness
• brightness
• buoyancy
• cheer
• cheerfulness
• geniality
• gladness
• gladsomeness
• happiness
• hope
• hopefulness
• idealism
• perfectionism
• pleasantness
• positivism
• radiance
• sanguineness
• sanguinity
• sunniness
• utopianism
• winsomeness