I previously argued that practical reasoning is intimately tied to actions, not act-sequences. One possible response (which I owe to Doug Portmore) is to say that our practical reasoning can conclude in an intention to φ, where "‘φ’ can stand for either some basic act or some act-sequence which contains a sequence of basic acts performed over some temporally extended time period."
I'm happy to countenance complex actions, like firing a gun or driving to the store. Despite comprising "a sequence of basic acts performed over some temporally extended time period", complex actions are not mere sequences. They're things we can do with a single 'exercise of agency', so to speak. That is to say: even if they won't be completed until a future time, they're still things I can decide to do now, and my decision will be effective. Complex actions may thus be included among the options available for my present self to choose.
Not all act-sequences are like this, because how we act in future is not always under our present deliberative control in this way. Sometimes, the intentions we form now will (predictably) fail to prove effective. I take it that this is what's meant to be going on in Jackson's famous "Professor Procrastinate" case. PP might fully intend to complete the book review on time when he agrees to do it. But he won't achieve this: as his track record has established, time and again, when it comes time to actually write the review he will find some excuse to delay. His prior good intentions come to nothing. Since he should have known this would happen (and, the case stipulates, it's worse to delay a review than to immediately decline it), Actualists argue that he should not have agreed to review the book. Intrapersonal co-ordination problems are in this way normatively similar to interpersonal ones: when you know that your future self is a defector, only a fool co-operates. You should do what will actually be for the best, not what could possibly be best, if only the other agent would (contrary to fact) cooperate.
Returning to the original question: Can we have reasons for [intending to perform] mere act-sequences in addition to reasons for [intending] actions? First, I reply that we can have reasons for intending complex actions (i.e. sequences that are within our present deliberative control). Can we further have reasons for intending mere sequences? This is less clear to me.
There seems something defective about forming predictably ineffective intentions. If you know that your future self will override your present intention to φ, how can you maintain the intention? (You might hope to trick yourself into forgetting that you won't actually φ, as one might attempt in response to Kavka's toxin puzzle, but I take it this is just a case of attempting to manipulate oneself into holding an irrational intention.) What about an intermediate case, where your present intention has (say) a 50% chance of proving effective? Perhaps you could then maintain the intention, in a hopeful spirit; though whether one should do so will presumably depend on the expected utilities. For example, if the expected value of accepting the book review, given a 50% chance of completing it on time, exceeds that of declining, then that's what Prof. Procrastinate should do. Otherwise, he should still decline.
So I guess we can, in this way, find a modest place in our ethics for long-term intentions of questionable efficacy. But their deontic status is largely determined by the agent's present scope of control. In particular, the mere fact that an act-sequence would be best is not sufficient reason to intend to do it, if the early steps are actually far more likely to lead to disaster. On the other hand, the actualist can certainly endorse forming effective long-term intentions. As I emphasized in my original response to Portmore, Actualists insist that we pick the best of our present options, which may include protecting against future vice. For example, our present options may include the forming of resolutions or long term plans or commitments that can reasonably be expected to sway our future behaviour. Actualists will straightforwardly advise choosing such options when they would lead to the best outcomes.
The dispute, I take it, is whether one should presently intend (and begin to carry out) an intrinsically desirable course of action that would unfortunately be averted in disastrous fashion by one's future choices. The possibilist says yes: it suffices that one's future self could have chosen to stay on the path to utopia -- that is reason enough for one's present self to start on this path. For the actualist, it makes all the difference in the world whether one's present good intentions will actually prove effective. If not -- if, despite your present best efforts, your future self will choose to defect and turn you down the road to hell instead -- then you'd best avoid this imprudently risky journey altogether. Good as the utopian act-sequence might be, it is not an option (action) available to your present self to choose. To nonetheless advise planning and acting as if it were, is (it seems to me) to advise delusion.