Marcus Aurelius -

The opinion of ten thousand men is of no value if none of them know anything about the subject.

F.A.Hayek -

It was John Maynard Keynes, a man of great intellect but limited knowledge of economic theory, who ultimately succeeded in rehabilitating a view long the preserve of cranks with whom he openly sympathised.

Robert Heinlein -

Throughout history, poverty is the normal condition of man. Advances which permit this norm to be exceeded — here and there, now and then — are the work of an extremely small minority, frequently despised, often condemned, and almost always opposed by all right-thinking people. Whenever this tiny minority is kept from creating, or (as sometimes happens) is driven out of a society, the people then slip back into abject poverty. This is known as “bad luck.”