Aesthetics (or esthetics) can be defined as the study of beauty and taste. The world is a place of extreme diversity, and taste is extremely subjective. What one person considers beautiful, another can consider revolting because of past personal experiences. Also, the spiritual aspect is sometimes confusing. Beauty is sometimes deceptive or not outwardly visible. The realm of experience includes the beautiful, the ugly, the sublime, the elegant, the sensuous, the charming, and the provoking. Each person must decide for himself which experiences he enjoys and dislikes. Aesthetics is, perhaps, the most subjective of the five branches of philosophy.