I keep on regretting putting my two cents into these threads. I keep thinking that I can make a brief helpful comment, but inevitably I end up getting drawn into a debate. So this will be my last post here for a while.
All causality is an entity causing itself to do something, so it is not surprising that Isaac can reformulate causal statements to bring that point out.
However, some of his specific reformulations rest on confusions. The concept "nature" conceptualizes an entity from a certain perspective (viz. as a metaphysically-given cause of actions). It is not valid to simply substitute "my nature" for "me" in sentences, just as it is not valid to substitute "my existence" or "my identity" for "me" into sentences. You can't say, for example, "My nature gave my existence's girlfriend's being the actuality of a card that said 'Be my unity's valentine'". The problem with that isn't just that this sentence is cumbersome. It is a misuse of all the metaphysical jargon I threw in there. It is true that existence is identity and identity is nature. But that does not make the concepts equivalent. Each concept gives a different perspective. And that perspective is necessary and valid only in certain contexts.
(Incidentally, in 99 out of 100 cases, if you're tempted to write an equal sign between two concepts, there is something seriously wrong with your thinking.)
Now human beings cause actions in a special way that is not predetermined by past events. Not all aspects of all of our actions are metaphysically given. So it is wrong to say that, in a case where we have a choice, our nature determines the action. That would obliterate the concept "choice" altogether. If you want to use the language of "nature", the proper formulation would be that our nature determines *that* we will choose but not *what* we will choose. What we choose is caused by *us* in a *different way*. It is precisely this different type of causation that gives rise to the need for the concept "choice".
Now when I say what we choose is caused by *us* rather than our natures, what exactly does this mean? The nature of a thing is that thing *qua* necessitator of actions. But what we choose is caused by us *qua* *chooser* of actions.
Now, if this all seems convoluted, it's because, it's because it is designed to make a very simple point accessible from within a warped rationalistic context. The direct way to come at the issue is just to notice that we can choose and that causing something by choice is different from causing it in some other way. For example, choosing to blink is different from blinking automatically (e.g., when dust enters your eye), though both are caused by you. That difference is self-evident and, in the end, that is all that the issue of freewill vs. determinism turns on.
Isaac claims that the law of causality (or the concept of nature, or whatever) rules out the possibility of (non-predetermined) choice. But what's the basis for this claim? Where does he get his (overly narrow) conception of causality? Where does he get the concept "nature"? The argument is nothing but a string of words.
If we detach our concepts from the facts that give rise to the need for them and write them neatly on pieces of paper in strings with equal signs and arrows, we can create all sorts of very rigorous feeling proofs, but it's all meaningless and it just leads to confusion. Parmenides, for example, "proved" in this way that motion and plurality were impossible, inaugurating two centuries of vexed absurdity. All of this was solved when Aristotle simply (but brilliantly) turned his attention to the facts that gave rise to the relevant concepts, at which point all the tangled webs of pseudo-logic dissolved making progress possible. Let's follow his example in philosophy rather than tying our minds in knots by emptying his concepts of meaning and playing word-games with their carcasses.
