11 A. The doctrine

1. Locke (Second Treatise, 1689): legislative and executive powers must be in different hands, lest makers of law execute their own wishes.2. Montesquieu (The Spirit of the Laws, 1748) — the classic formulation: "When the legislative and executive powers are united in the same person or body… there can be no liberty… were the power of judging joined to the legislative, the life and liberty of the subject would be exposed to arbitrary control." Political liberty exists only where power checks power.3. The pure model (USA): three branches, separately recruited, each with its own function, no overlap of personnel.4. The modified model (Westminster/Nepal): separation of functions is retained in outline, but personnel overlap (ministers sit in parliament) and powers interpenetrate — balanced not by separation alone but by checks and balances.