Sometimes people use the word “possible” to mean something like, “does not entail a contradiction.” This sense of “possible” is narrower than “consistent with the laws of nature.” I gather this is what Thomas Pogge was alluding to when he said that there is a sense of “possible” that coincides with “conceivable.” Some have raised worries about whether conceivability implies possibility in this more narrow sense. Here’s an interesting example from Barry Stroud’s book on Hume (p. 50). Goldbach’s Conjecture states that every even number is the sum of two primes. At this point (as far as I know) no one has offered a proof of Goldbach’s Conjecture, and no one has disproved it either. If Goldbach’s Conjecture is false, it presumably says something that is not possible (in the narrow sense). But one might argue that I can nevertheless conceive of a state of affairs in which someone proves that Goldbach’s Conjecture is true. In that case, it seems, I would have conceived of something impossible. ...

I'm not an authority on Mach, but (as Peter Lipton suggests) some of the philosophers who believe that “the world consists entirely of sensations” do not think they are thereby committed to solipsism. One obstacle for this view is how to account for the possibility that more than one mind can perceive the same object. When I see a table, on this view, the table is just a collection of sensations in my mind. When you see a table, it’s a collection of sensations in your mind. So how is it possible for us to see the same table?

I'm not sure I understand what it is for something to "matter", if it isn't shorthand for mattering to someone or other. As Richard Heck points out, something a person does might matter to other people after her death. And certain things I do matter very much to me right now–or will matter to me later on–even though I know that I will die someday. Perhaps there will come a time when there's no one left in the world—at that point, "nothing will matter" in the sense that there will no longer be anyone to whom anything could matter. But it doesn't follow that the things we do now matter very much (to ourselves or to our descendents). I also don't see how the possibility that "the world is all an illusion" should affect the issue. Perhaps if this possibility were actual, then many of the things that I assume will matter to other people will not really matter, since in that case no other people would exist. (Though there may still be things that matter to me.) For example, one might argue that...

I wouldn't say that there is a "current philosophical standpoint" about the idea of the "embodied mind," but I do think it's something that many philosophers of mind are sympathetic to these days. Here are two recommendations for further reading: 1) "Being There: Putting Brain, Body and World Together Again," by Andy Clark 2) "Action in Perception," by Alva Noe.

It might help to distinguish between imagination and perception. There's a sense in which what I perceive is not up to me. Although I can control what I see by turning my head, opening or closing my eyes, or taking off my glasses, once I've done those kinds of things, what I see as a result is out of my control. If someone orders me to see an elephant in the middle of my living room, it's not clear how I could carry out that command (aside from calling the zoo and asking if they deliver). On the other hand, I can easily imagine an elephant in my living room. Though as Peter Lipton mentioned, some philosophers (e.g., Locke, Hume) thought that what we can imagine is limited to what we can cobble together from materials acquired through perception.

One way to approach this question is to think about what sorts of properties are morally significant. Some properties--such as the capacity to suffer or feel pain--might belong to a developing human life at some stages, but not others. A zygote probably doesn't feel pain, but it's plausible that an eight month old fetus does.