The consequence argument is as follows: If we have no power over X, and X completely determines Y, then we have no power over Y. If determinism is true, then the past and the laws of nature together completely determine the future. We have no power over the past or over the laws of nature. Thus, if determinism is true, then we have no power over the future. Thus, free will and determinism are incompatible.
I've posted on the Consequence Argument a couple times in the past. My conclusion was that the argument is flawed because it ignores the role the present plays in the way the past shapes the future. If we recognize the present as an integral part of the process by which the future is determined, then the argument loses its force.
I want to elaborate on my point of view and point out some weaknesses with the Consequence Argument. I am not a staunch determinist. However, I do think that any coherent notion of free will (that is, any free will worth having) is compatible with determinism. Thus, for the sake of argument, in the rest of this post I am going to assume that determinism is true.
Consider how supporters of the Consequence Argument might counter me. They might say that, even if the present is an integral part in determining the future, the present has no power over the future, because how the present shapes the future must also be determined by the past, and the present has no power over the past. The implication is that if we attribute power to some entity, that power cannot be completely determined by any prior entity. The logical result of this point is that only a first cause can have power in the universe--that is, unless we allow for time-reversed causality.
If we allow for time-reversed causality, the Consequence Argument loses all of its force. For, if the present has causal influence over the past, then we in the present have power over the past, and so we have power over that which has power over the future. If, on the other hand, we don't allow for time-reversed causality, we back the Consequence Argument into a tight corner. This is regardless of how people respond to my previous argument. Consider . . .
If causality only works forwards in time, then any event at T2 cannot have power over events at T1. Therefore, any event at T2 cannot have power over the future, because it is completely determined by some prior event which has complete power over the future. Remember that, according to the Consequence Argument, if X completely determines Y, then only that which determines X can have power over Y. If the more recent past has no power over the less recent past, then the more recent past cannot have any power over the future. Since every event is caused by a prior event, then no particular event in the past can be said to have power over the future, unless we stipulate a first cause--a cause which completely determines everything, but which itself is not caused by anything.
I don't think determinism benefits at all from the hypothesis of a first cause. On the contrary, I think the idea of a first cause is more of a nuisance than a laudable explanatory hypothesis.
If we don't assume a first cause, we can attribute causal powers to all past times equally, in which case we are justified (indeed, obligated) to attribute them to the present.
We might say that all events at all times completely determine each other. Or perhaps the notions of a universal past, present and future are incoherent, and that the past/present/future distinction only works locally. In that case, perhaps causality itself only makes sense as a way of interpreting local phenomena, and not the universe as a whole. I think I should explore this line of thought more. In any event, either we accept that there is/was a first (and only) cause at the "beginning" of the universe, or we reject the Consequence Argument.