… is from the great Jacob Viner’s classic 1928 article “Adam Smith and Laissez Faire”; here, specifically, from page 142 of the 1966 A.M. Kelley reprint of the 1928 volume Adam Smith: 1776-1926:
Even when Smith was prepared to admit that the system of natural liberty would not serve the public welfare with optimal effectiveness, he did not feel driven necessarily to the conclusion that government intervention was preferable to laissez faire. The evils of unrestrained selfishness might be better that the evils of incompetent and corrupt government.
I add only that nothing removes the restraints on selfishness more readily and surely than does access to government power.