You should read the essay "Science: Conjectures and Refutations" by Karl Popper. In short, although astrology may use things like observation, it is not scientific. Why? Well you answered your own question, it's made up of extremely vague statements that will always be true. The virtue of a scientific theory is not in its ability to be proven true, but its ability to be proven untrue.
Let me use a simple analogy:
Let's say I tell you that I have a theory about why people commit murder. I say the sole reason why people are killers is because they had poor relationships with their parents, or if they were orphans with the major... (read 620 more words →)
You should read the essay "Science: Conjectures and Refutations" by Karl Popper. In short, although astrology may use things like observation, it is not scientific. Why? Well you answered your own question, it's made up of extremely vague statements that will always be true. The virtue of a scientific theory is not in its ability to be proven true, but its ability to be proven untrue.
Let me use a simple analogy:
Let's say I tell you that I have a theory about why people commit murder. I say the sole reason why people are killers is because they had poor relationships with their parents, or if they were orphans with the major... (read 620 more words →)