Sufficient appearances will never be wanting to those who have a mind to deceive themselves.
 Edmund Burke, Thoughts on the Cause of the Present Discontents (1770). copy citation

Context

“because I will not assert, that there is no difficulty in the art of Government. Undoubtedly the very best Administration must encounter a great deal of opposition; and the very worst will find moresupport than it deserves. Sufficient appearances will never be wanting to those who have a mind to deceive themselves. It is a fallacy in constant use with those who would level all, things, and confound right with wrong, to insist upon the inconveniencies which are attached to every choice, without taking into consideration the different weight and consequence of those inconveniencies.” source