Science, as most people imagine it, does not exist. There is no way of collecting data of any kind without the interference of the subject themselves. If you use an instrument, that tool was designed by people, and those people had a certain bias or interest in mind when they designed it. They decided, among other things, what it is the instrument would register and that everything else would be disregarded. A thermometer can't tell what size your feet are.
No equipment can register data it was not constructed to perceive. We are the ones who decide what it is we want to know, and we design tools that will gather data that we think are important or relevant about the object of our observation. Most scientific breakthroughs do not come from more advanced equipment but a change in perspective. Somebody suddenly has an idea to look for something nobody has looked for before. They design an instrument that can gather the data they need, and they construct a new model of reality.
The only problem is, that contemporary science treats every breakthrough as if we got closer to grasping the totality of reality with each step, and there is a dogma that we will eventually get there, and the one and only path is that of Holy Science. I'm sorry, I fail to see how this is possible, and I also fail to see the objectivity or the "quest for truth" here. It's rather the quest for power over people's minds, not so different from the "dark middle ages". I distrust any collective system of thought that discourages people from directly experiencing the world around them and thinking with their own head.
Divinatory systems have two very important elements. One is establishing the right attitude, and the other is developing a method or way of interpretation. Some systems put greater emphasis on this, others on that, but most treat them as equal.
The right attitude is important because, unlike science, divinatory systems do not disregard the fact that the cards on the table or the planets in the chart are tools that can only aid you in ways your bias or your disposition allows them to. Using any kind of divinatory system requires that on the one hand, you dedicate yourself to become more and more aware of your conscious and not so conscious perspectives and beliefs, fears, hopes, etc, and on the other, you need to find a way to, at least temporarily, suspend them. I can't imagine any genuine divination without doing this.
And method is important because it helps you maintain your focus, it's like a compass that helps you find your way in a landscape that is ever-changing... Without it, you are just having a "good trip".
The tarot is more "obvious" about attitude and less obvious about a method. It does not mean, however, that there is none, it only means that it has to be developed by each individual themselves, you decide how simple or intricate you want your readings to be.
I have only spent a few months with astrology so far, but it is more "obvious" about method than the tarot, and it seems to able to draw a more elaborate "map" of the landscape of the soul, but it does not mean that it is not important to work on developing the right attitude.