That is alchemy's first law of Equivalent Exchange. To obtain, something of equal value must be lost. Recurring Quotes Alphonse (Introduction, episodes 2-41): Humankind cannot gain anything without first giving something in return. 3.4 Fullmetal Alchemist: Sonata of Memories (GB).3.3 FullMetal Alchemist: Straying Rondo (GB).3.2 Fullmetal Alchemist: Broken Angel (PS2).3.1 FullMetal Alchemist 2: Curse of the Crimson Elixir (PS2).2.45 A Rotten Heart (One who lets her Heart Rot).

2.39 Secret of Ishbal (Eastern Civil War).

2.37.2 The Mystery of Warehouse 13 (The Mystery of the 13th Warehouse).

2.37.1 The Bachelor Lieutenant (The Fighting Lieutenant).

2.36 The Sinner Within (Our Inner Sinner).

2.34 Theory of Avarice (The Theory of Greed).2.30 Assault on Southern Headquarters.2.29 Untainted Child (Innocent Child).2.25 Words of Farewell (Farewell Ceremony).2.24 Bonding Memories (Affixing Memories).2.23 Heart of Steel (Fullmetal Heart).2.20 Soul of the Guardian (The Guardian's Soul).2.17 House of the Waiting Family (The Home Where the Family Waits).2.12 The Other Brothers Elric (Gravel Earth) - Part 2.2.11 The Other Brothers Elric (Gravel Earth) - Part 1.

2.10 The Phantom Thief (Thief Psiren).2.7 Night of the Chimera's Cry (The Night the Chimera Cries).2.5 The Man with the Mechanical Arm (Dash! Automail).2.4 A Forger's Love (Transmutation of Love).2.2 Body of the Sanctioned (Body of Taboo).2.1 To Challenge the Sun (One who Challenges the Sun).

Full metal alchemist