-- Franklin D. Roosevelt
At first I thought he had it backwards. But then I saw that by "realization" he probably meant "to make thoughts real". And then it makes kind of sense.
But if we take the word to mean "new understandings", then it really is backwards. I think the premier barrier to new understandings is too much certainty. Doubt is not pleasant, but I think it's a necessary part of the process of elevation, and a loooong one.
"I dream, therefore I become."
-- Cheryl Renée Grossman
"I dream, therefore I come."
-- unknown teenage boy
Tarran says re the Roosevelt one:
Nah, you are completely getting it wrong.
That statement was an attempt to refute claims by FDR's critics that his policies would have bad economic consequences (it is instructive to note that the Great Depression ended shortly after his successor abandoned those policies BTW).
The critics were pointing out that the U.S. economy lacked the resources to behave in the way he envisioned. That was his response, basically accusing them of sabotaging the future.
Of course his critics were right. A strongly held belief that is at variance with natural laws or praxeology is merely delusional. If I think I float, no matter how strongly I believe I float, I will still be yanked to the ground by gravity.