This statement isn't technically accurate, of course, but it carries heavy meaning. A more accurate rendition would read: "If you repeat a lie often enough, it becomes a supertruth."
I've been using the word "supertruth" for a few months now, and to my knowledge, I made it up. It's a very useful term, and my purpose in this short post is to define it. So...
Supertruth, n.: A proposition held as true regardless of its actual validity.Immediately upon reading this definition, we see what Goebbels was getting at in his famous utterance of how propaganda works. He was stating that uncritical acceptance, even to the point of defending a falsehood, is something that humans are prone to, and indeed something we are so prone to that we can be manipulated into doing it rather easily.
Supertruths form the bases of religions, political ideologies, and, indeed, much of how we get around on a day-to-day basis--as they close the gaps between our lack of actual confidence and our self-assuredness. Dogma, for what it is worth, is a class of supertruths--those that proceed from an authority. The connotation, generally, is "propositions held above any examination of their truth-value." Another popular word related here is that supertruths possess a certain amount of "truthiness."
Supertruths, it should be noted, can actually be true. For example, to draw from a popular political topic currently, "firearm ownership prevents crimes." This, no doubt, is true in many cases, but that's usually not why many people accept it. It also, of course, sweeps an awful lot under the rug, oversimplifying a complex issue, because the sense of control provided by accepting the statement is worth more than the actual validity of the statement. No doubt, many people would still maintain this supertruth even if it were demonstrated to be entirely false.
Another class of realms in which we will find many supertruths that may actually be valid are those where we cannot have complete knowledge due, usually, to complexity. Significant examples of such realms include economics, health/well-being, nutrition, and morality--fields that are still at least significantly arts, even if science is making inroads upon them.
On the other hand, supertruths, of course, need not be true, and often they are not. "Jesus lives (or saves)!" for example, is sheer nonsense, and yet billions maintain it. "Islam is a religion of peace" is another good, relevant example with massively significant consequences.
The examples of supertruths are myriad, so I don't intend to elaborate more on them here. This piece is merely intended to be a definition of a term I'm finding very useful. Therefore, I also do not intend to delve into the complex psychological and social reasons that human beings are so ready and insistent upon holding (and failing to re-examine) supertruths.