Could a person practice both critical thinking and astrology? I believe one can, but only for a short time. Here is why: if you study and practice critical thinking methodically, you are going to apply it to most of aspects of your life. So you will apply it to methods and principles of astrology. What happens next depends on your view of astrology and how do you use it.
One of principles of critical thinking is a following disposition: one should change his belief when he faces a sufficient number of new facts. So if you think that astrology can give good predictions you may want to know how does it works. And you may want to test how correct are these predictions. As far as I know there are much more evidence that western astrology gives predictions that aren’t better then random ones, but you can look for relevant studies yourself. So if you use astrology to produce any kinds of predictions you may stop doing so.
In the same time if you write horoscopes for a magazine or for a web-site, and this activity bring you money you may want to continue doing it. For example you can reason like this: if people want to be fooled by my incorrect predictions, let them be fooled; I will get some money, they will get more confidence and some good emotions. I can also note that critical thinking wouldn’t make you a moral person, so it couldn’t stop you creating horoscopes for profit. In the same time critical thinking can change one’s point of view on morality 1.
Astrology can also be used for a number things besides making predictions. You can give a knowledge of astrology to a character of your story. You can use it to produce aesthetically pleasing images and even sell them for money. You can use you knowledge of astrology to participate in debates with known astrologers. You can write a study about different aspects of astrology: its history, traditions, and other things.
So even if you aren’t going to use astrology to make predictions you still can use it in a number of ways, because it contains a vast amount of knowledge. So I can conclude that some of aspects of astrology can conflict with critical thinking, but some can be compatible. It also depends on a personal approach, so you can learn critical thinking and try yourself.
1. ^ : Moral Reasoning