Edmund Burke Quote

The science of constructing a commonwealth or renovating it, or reforming it, is...not to be taught a priori...That which in the first instance is prejudicial may be excellent in its remoter operation, and its excellence may rise even from the ill effects it produces in the beginning. The reverse also happens; and very plausible schemes, with very pleasing commencements, have often shameful and lamentable conclusions.

Reflections on the Revolution in France (ed. 1790)