Astrological Destiny and Free Will
Others, such as Dane Rudyar have argued that decisions are not the result of free will, but the process by which we make them is, and that the only true free will is the will to destiny. This presents a very disempowering view of the world where we are mechanistic in our beliefs and our actions, and in general, this seems to suppose that our concept of free will is largely relegated to menial tasks. It is also generally at odds with the general observation that we all grow and learn to use our talents in different ways.
Many older societies had a dual concept of fate which allowed for free will in large part. The twin Hindu concepts of Karma and Dharma for example create a paradigm where part of fate is the result of past decisions and part is what is given to one. This is similar to the Germanic concepts of Orlog (Primal Law) and Urdh (What has turned), except that Urdh is a bit less personal than Karma and represents the general weight of the past. In this view, astrology can only provide insight into a part of one's fate, that primal law which is written for each of our lives. It cannot tell us how we will choose to act and hence what we will accomplish in life, that these things are up to us. So what is the role of this aspect of fate?
Astrology reached its height in complexity at a time when it was largely practiced by Arab and later European Neoplatonists. The cosmology which was used by these people was borrowed from Jewish interpretations of the Neoplatonic concept of Godhead. This model allowed for four emenationist levels in the development of any action. At the first level (the World of Nearness), each concept exists but as a ray extending out from Godhead. The next level (World of Creation) provides a form of a form of a concept and is the first level where the concept is distinct from anything else. The third level (World of Formation) sees some additional fleshing out and differentiation, and finally in the World of Action, the concept becomes actionable. As one moves a concept back towards The World of Nearness, it becomes more abstract but more flexible while as one moves the concept towards The World of Action, it becomes more concrete and defined.
In this model, Astrology charts describe the reality in the World of Creation. They are extremely abstract, and rather than impelling one to act a certain way or have certain circumstances in one's life, they merely describe in these abstract terms the life a person will lead. Yet due to that abstraction, the individual has a great deal of freedom regarding how any given part of the chart will manifest. While fighting the chart may well be futile, channeling certain tendencies out in productive ways is not.
A second point worth making here is that we are capable of creating some change in every level of reality in the 4-world model. As Paracelsus pointed out, anything that the planets can do, so can we accomplish. This can be done through occult ritual, through meditation, or through the discipline of conscious living. In the end, we are never condemned to be cursed by the afflictions shown in our natal charts.
There may be some points in our lives which are truly inescapable. For example, we all die and if we are lucky to live long enough, will all experience the loss of our parents. There are many other points that are easily escapable (so-and-so might get a traffic ticket next Wednesday, for example). Most of the big events in our lives exist somewhere in the middle.