Possible Clues:

• 'It's ___, not a science'
• Not a science, but ___
• "What I dream of is __ of balance ... ": Matisse
• "Excellence is __ won by training and habituation": Aristotle
• 'Conversation is ___ in which a man has all mankind for his competitors': Ralph Waldo Emerson
• "Dying is ---": Plath
• 'Dying / Is ___, like anything else': Sylvia Plath