This really won't mean much to you if you haven't studied determinism, and it is only a 250 word work requirement, but I thought I'd post it to mark the occasion.
Freedom, Mind and Value 2006
1. Explain in your own words, and using your own examples, the idea of causally necessary conditions and causally sufficient conditions.
When anything happens in this world; for example a car crash, a leaf falling from a tree or a flood - we attribute a range of causes to that event. We could say that a driver's speed caused the crash, or excessive rain caused the flood. In the language of philosophy we call that causation. But, as we shall see, it is only in a very rare instance that we can attribute a single cause to an occurrence. It is based on this that we define causes into two categories: Causally necessary and causally sufficient.
Let's take the example of a flood. Most people would cite excessive rain as the reason for a flood. But, really, excessive rain would not be the sole reason for flooding. A flood would obviously be caused by a combination of individual necessary circumstances, such as breached levies, depressed terrain or soil erosion. If you extracted those factors the event wouldn't have happened. We would, therefore, categorize individual conditions such as excessive rain as causally necessary, because the flood wouldn't have happened without them.
As stated, it would be impossible to suggest that any one condition, such as excessive rain, was sufficient for a flood. Excessive rain may be necessary for a flood to occur, however it may not be sufficient. This is because several factors (breached levies, soil erosion) must have contributed to it. When taking into account all the necessary symptoms that must have been present for a flood we term them as causally sufficient.
In summary we have two categories which define causation - causally necessary forces, which have to be present in order for something to occur; and causally sufficient forces, those necessary but separate forces which combine to make something occur.