Good point. but... a hour ago, I was reading an interesting thread and I was tempted to respond. But then I decided it was not necessary. As you can see, I used my free will.
There is another factor at play here that you missed. There is a reason why it seemed unnecessary to reply, it wasn't a spontaneous decision, something came upon you that made you feel it was unnecessary to respond.
Suggestions, but not guarantees (since I am not you and do not know exactly what happened): Maybe you did not feel it was worth writing which would in itself be a factor of cause and effect, but even that feeling was influenced by comparing the values of writing the post out and the reading of that writing, and then decided the compared values were not needed.
Well...I would agree on your speech, if you proved me that man has no strength of will. Actually man does have it. When a person has a big strength of will, all the external influences have no effect on him.
So the cause-effect system doesn't work on a person with a big strength of will.
To avoid getting down and dirty in hard determinism, let's say man does have the power to make decisions. These decisions are still influenced by factors outside of it. For example; your beliefs are from observations and conclusions drawn from your reasoning, and thus your choice of beliefs were influenced by those. Another example would be that: I would not put a frown emoticon after saying "happy birthday" I choose to put a smiley face on it because of the factors: the post has a happy tone to it, that it fits more with the post.
I understand that very few people have a big strength of will. However I like your way of reasoning very much.
I appreciate it, and I like yours as well.