The fatal effects of bad government arise from nothing, but that it does not sufficiently guard against the mischiefs which human wickedness gives occasion to.
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

Context

“Whatever beauty, therefore, can belong to civil government upon account of its utility, must in a far superior degree belong to these. On the contrary, what civil policy can be so ruinous and destructive as the vices of men? The fatal effects of bad government arise from nothing, but that it does not sufficiently guard against the mischiefs which human wickedness gives occasion to. This beauty and deformity which characters appear to derive from their usefulness or inconveniency, are apt to strike, in a peculiar manner, those who consider, in an abstract and philosophical light, the actions and conduct of mankind.” source