>> Yes, and the possibility of falsification is required for science. It's not a convenient option.
> According to Popper's definition.
Karl Popper didn't invent falsifiability, he discovered it. But I see you have a very common belief that falsifiability is optional, and that things can be called science that don't have this essential property. So let's do a thought experiment in which falsifiable theories aren't required -- let's see where this takes us.
Let's say I'm a doctor and I've created a revolutionary cure for the common cold. My cure is to shake a dried gourd over the cold sufferer until he gets better. The cure might take a week, but it always works. My method is repeatable and perfectly reliable, and I've published my cure in a refereed scientific journal (there are now any number of phony refereed scientific journals). And, because (in this thought experiment) science can get along without defining theories, I'm under no obligation to try to explain my cure, or consider alternative explanations for my breakthrough — I only have to describe it, just like a psychologist.
Because I've cured the common cold, and because I've met all the requirements that psychology recognizes for science, I deserve a Nobel Prize. Yes or no?
Ask yourself what's wrong with this picture, and notice that the same thing is wrong with psychology — all description, no explanation, no established principles on which different psychologists agree, no effort to build consensus, and no unifying theories.
> You give only one test for what is a science and ignore all the others.
There is only one test. It's a matter of common sense, philosophy, and law. The definition I gave, and provided references for, is written into the law, for a number of reasons including people's desire to keep religion out of public school classrooms. The Discovery Institute, that hotbed of Creationism, make the same argument you're making -- science isn't strictly defined, it's all a matter of opinion, and Evolution is just a silly idea cooked up by some eggheads.
> I don't know why you have singled out psychology and psychiatry for this treatment.
Easily explained. Sociologists and astrologers aren't scientific, but they don't have clinics and they don't mislead parents and children, invent imaginary illnesses for them to have. Physicists are scientists, but they don't have clinics and they don't presume to treat your ills. Doctors have clinics, but they're reasonably scientific, and when they're not, they can be sued within an inch of their lives, sometimes even thrown in jail.
Psychiatrists and psychologists are in a class by themselves -- they masquerade as scientists, some ill-educated people think they're scientists, psychiatrists can dispense rather dangerous drugs, but neither they nor psychologists are remotely scientific. And best of all, they don't have to accept adult responsibilities.
Rebecca Riley was diagnosed with bipolar syndrome and ADHD at the age of two, with the encouragement of her parents, who were already making $30,000 per year from Social Security payments for their other children, diagnosed earlier with bogus mental illnesses and already a walking gold mine. But Rebecca was their finest moment, and that of her psychiatrist. Rebecca died at age four from the drugs her parents and psychiatrist encouraged her to take.
Her parents were convicted of murder. Her psychiatrist is still practicing. Sort it out for yourself.
http://en.wikipedia.org/wiki/Rebecca_Riley