Well to use a simple example, look again at the chemical reaction example I gave before. At any one time there is only one set of chemicals present that can react together in the experiment and only one set of conditions that the experiment is exposed to during the experiment. In other words it can't be both 32 degree C and 100 degrees C at the same time, the pressure can't be both 100 bars and 10,000 bars at the same time, you can't have just one gram of carbon and at the same time have 40 kilograms of carbon. So at any one time only one set of conditions exist for any chemical reaction and thus there is only one possible outcome of that reaction. If there happens to be an unexpected result it is because there was a factor which you either were unaware of or had miscalculated.
Or take an example from physics, like vector calulations. You have all these various forces acting upon an object at the same time. Does the object take off in more than one direction at a time? NO! All the vectors add themselves to gether or cancel eachother out to various degrees and the result is an object moving in a single direction until acted upon again by additional forces.
This is true of all causal events. The complexity of the circumstances makes no difference. If everything happens purely as a result of some causal chain of events then regardless of how many causes you pile up on one another, they only have one possible result. The onyl way I know of that the idea of morality can survive this is the acknowledgement of something supernatural. Such things do not necessarily work the same way as purely natural things do. And since God and a good part of ourselves are both supernatural we are not entirely subject to Causal Determinism.
Resting in Him,
Clete