Is the mainstream economics a science?

I like to collect citations from well-known economists. They actually think that economics is a hard science and they are scientists in terms of methodology.  Sometimes they give direct examples and compare economics with some hard sciences. This is one of examples from R.Schiller who compares economics and medicine:
Imagine how the medical profession would view one of its members who recommended to the general public some therapy that had not yet passed scrutiny from the appropriate authorities. Medical professionals know how often seemingly promising new therapies turn out, after careful study, not to work, or even to be harmful. There is a rigorous process of scholarly review of proposed new therapies, associated with professional journals that uphold high research standards. Circumventing that process and promoting new, untested ideas to the general public is unprofessional.
By irony, Robert explains the difference between the medical profession and economists in the very beginning of his post:
... An apparent paradox emerged from the discussion: the boom in popular economics comes at a time when the general public seems to have lost faith in professional economists, because almost all of us failed to predict, or even warn of, the current economic crisis, the biggest since the Great Depression.

Imagine now that the medical profession has the same "success" in the main fields of research. Would anybody go to a  doctor at all?  What were the criteria of " ... scrutiny from the appropriate authorities"  in the economics profession?

Please, do not steal from the hard sciences the merits economics does not deserve. There is no scientific methodology in the current economic knowledge because economits explicitly deny the necessity to compare observations and predictions. This is the core of medical scrutiny.  If to compare an economist and a doctor, the former should never approach the patient.