If I have a sudden hankering to eat raspberries, it strikes me that I might want not want to eat them as a means to any end. I just want to eat some raspberries. So it's not derivative in any causal sense--it's not that I want this because it's a means of getting something else, and it's not obviously a result of some other desire. But our various desires might fall into natural classes. Wanting raspberries perhaps falls into the same class as wanting chocolate, and into a different class from wanting to get together with a friend. Wanting to eat some rasperries is an "instance" (that's the word I'd use) of some general type--it's an aesthetic desire, rather than a desire for interaction. If all humans have a set of fundamental desires like this, I think the list of them is quite long, and a lot of our specific desires fall into many categories, or resist categorization.

There are two different distinctions that are of interest here.

First, there is a distinction between ends and means. Going to the kitchen is a means to the end of eating food. That is one way in which your desire to go to the kitchen is derivative from your desire to eat. Given the complexities of achieving most of our ends (buying and cooking and preparing food, earning money to be able to buy food, setting the alarm in order to get to one's job in order to earn money, and so on), the majority of our desires are bound to be derivative in this sense.

Second, there is a distinction between original goals and evolved goals. The original goals of a child may be few and simple (to eat, to avoid pain, to be loved, etc.) while the evolved goals of an adult are many (to travel, to learn about plants, to enjoy music, to learn other languages, to have children, to deepen friendships, etc.). It would be a mistake to assume that the adult's many goals are all just means to the original goals of a child, however -- that enjoying music, for example, is really just a means to the original ends of a child. The fact that one desire develops out of another doesn't mean that its ultimate aim is the satisfaction of that first desire.

Good question, and I think it has a lot of philosophical import. Here's why. What we might call a "true lie" is one where the liar knows what she is doing. She knows that she needs to do or say something to alter what her target believes in order to get him to do something the liar wants. Contrast this with a "behavioristic lie," one that has the effect of getting the target to behave a certain way but without the "liar" knowing how she is doing it. Take the case of a 3-year-old girl who has learned that saying "I'm tired" often gets her out of doing something she doesn't want to do. One night her dad says "It's time to go to bed," so she repeats her standard ploy, "I'm tired." She does not seem to know how her lie works!

This difference between "true lying" and "behavioristic lying" seems to make a big difference. Behavioristic lying might not require any especially impressive cognitive abilities. Well, behavioristic learning itself is pretty impressive--and it allows more interesting and flexible forms of deception than, say, animal mimicry (the viceroy butterfly isn't doing anything cognitive in "pretending" to look like the poisonous monarch butterfly). But it's not as impressive as true lying. Your dog's behavior, if it is just behavioristic lying, does not seem to require understanding your mental states--your beliefs, desires, or intentions. Rather, your dog, like the 3-year-old girl, may have simply learned from past experience what works to get what she wants (e.g., to get fed or taken for a walk). Real lying, on the other hand, seems to require understanding that others perceive the world differently from you, they have different desires, beliefs, and intentions than your own. One cannot intentionally manipulate others' beliefs (i.e., truly lie) unless one understands that they have beliefs that can be manipulated (i.e., that can be false).

I happen to think the ability to "truly lie" may be unique to humans' (though perhaps it shows up in some other higher primates or dolphins or perhaps even dogs given their long co-evolution with humans). And I think it likely evolved because of our ancestors' complex social interactions (including reciprocal altruism) and in tandem with our remarkable ability to interpret, explain, and predict the behavior of others and ourselves in terms of beliefs, desires, intentions, etc. Once you've got that ability, you may be on your way to being able to think about alternative possibilities, choosing (freely) in light of such thinking about alternative future outcomes, thinking symbolically, doing philosophy, the whole shabang! Though I'm a bit leery of saying that so much of what makes us human is tied to our remarkable ability to truly lie...

The brain and nervous system "combine" information from different sensory modalities, so it is quite likely that when you visually perceive that you are about to be hit, other parts of your brain respond, including perhaps sensory systems that normally perceive pain in that part of the head and/or motor systems that prepare you to react to such a blow. There is a lot of interesting research showing that the same parts of the brain are active when you imagine performing an action (but don't perform it) as are active when you perform the action--sometimes you can start to feel your body doing something even though you don't move. Your situation might be sort of the reverse of this. The key is to remember that even though "nothing has happened" on the outside, lots can be happening on the inside--that is, in the brain, which of course, is the basis of our minds' feeling things.

You are raising really interesting questions that philosophers debate under the headings of "mental causation," "theory of action," and "free will." One way the problem gets generated is by assuming, as you do, that thoughts (including decisions or intentions) are immaterial things. That's what Descartes said, and ever since, the main objection to his view is your question--how could an immaterial thing causally interact with a physical thing like the brain (and vice versa, since on his view the physical world sends information through the brain to the mind which consciously experiences it--how the heck could that happen?).

The main response to this problem is by giving up your assumption of "dualism" and instead try to understand how thoughts and conscious experiences can be part of the physical world. That's no easy task. But one way to make the initial move in that direction is to see that the idea of non-physical or immaterial thoughts makes no more sense than the idea of physical thoughts. We simply have no clue what an immaterial soul or mind would be or how it would work and we have no idea how we might go about studying immaterial things. On the other hand, we are increasingly understanding how the brain works to produce thoughts, experiences, and actions, and we are beginning to understand how we might study consciousness and action in a way that combines first-person reports about how things seem to us with "hard" science approaches, such as neuroscience.

And if we assume that mental states just are brain states (or perhaps mental states "arise from"--without being distinct from--brain states), then we can begin to answer your question of how thoughts cause actions, since they are all part of the physical system.

Hope this helps!

I would like to focus on your last question: Is it possible that plants and animals have thoughts just like people? Let's take animals first. We are animals, so at least some animals have thoughts just like people. Our nearest animal relatives--the primates--probably have thoughts very much like ours, though (perhaps with a few very special exceptions) theirs differ from ours in that none of theirs are expressed in language (while some, if not all, of ours probably are). (The few very special exceptions would be those primates who have been taught various kinds of sign languages or artificial languages.) Going down the evolutionary tree, I'd be willing to say that other mammals have thoughts not unlike ours, etc. In fact, I'd be willing to say that any animal that has a suitably rich nervous system might have thoughts not unlike ours (what counts as "suitably rich" is open for debate, of course). In fact, I'll propose that having a nervous system (either biological or artificial) is a necessary condition for having thoughts.

That probably rules out plants.

Two comments on the central pair of assertions: "[T]houghts are not physical. They're metaphysical" -- one terminological (but not insignificant), the other more substantial.

(1) The terminological comment is this: "Metaphysical" does not mean "non-physical", "supernatural", or anything of that kind. Metaphysics is just the traditional label for a bunch of topics famously discussed -- though not for the first time! -- in Aristotle's Metaphysics.

That book, or rather collection of books, is so called because it was placed meta ta phusika, after the Physics, by ancient editors. Its topics include questions like what makes something an object rather than an event or process? must objects have essential properties and if so what? are numbers a kind of object? what is a cause? Now, those questions (and similar ones that we also nowadays by extension call metaphysical) raise very general issues. And you can see why the ancients might have been at a bit of a loss as to how to classify them, and so just called them -- in effect -- "the sort of questions that were dealt with by Aristotle after some more tractable questions of physics". But do note that they are mostly very general questions about the same world that e.g. science and mathematics addresses: they are not essentially questions about some further, supernatural or non-natural, realm. Indeed, lots of contemporary metaphysicians -- i.e. lots of theorists interested in such very general questions -- are naturalists, and suppose that the natural world that science and mathematics addresses is the only world there is. For more, see this Stanford Encyclopedia article.

(2) Leaving that aside, though: why should we suppose that thoughts are not physical? What does that mean? Is it true? After all, thoughts are states or events that dispose us to suitable actions: and we've every reason to suppose that our actions are non-spookily generated by neural events. So maybe talking about thoughts etc. is just another way of talking about those physical happenings (as it were, a software rather than a hardware level of description of the distributed processing system in our skulls).

And certainly, it isn't obvious that "thoughts are not physical", as the arguments in any introductory book in the philosophy of mind should make clear. (I still quite like this student-friendly book!)

First, take a look at Question 2384 and its answers, which are closely related to your question. Your question is related to what is called the "inverted spectrum", a philosophical puzzle posed by John Locke, one version of which is this: Is it possible that objects that have the color you describe as "red" are seen by me as if they had the color you describe as "green", even though I also describe them as red, and vice versa? Posing the problem is difficult; e.g., objects arguably don't "have" colors, but reflect light of certain wavelengths, which are perceived by us as certain colors. "Is the color that I perceive as, and call, red the same as the color that you perceive as what I call blue?" is another way of posing the puzzle. Part of the problem is that there doesn't seem to be any way to decide what the answer is (if, indeed, it has an answer). What experiment would decide between these? Perhaps such color-perceptions (more generally, what are called "qualia") are such that a functionally complete theory of the mind (or brain) would not enable us to distinguish between them. For more on this, see the Stanford Encyclopedia of Philosophy article on "Inverted Qualia".

"How can I hear my voice when I'm not speaking?" is your question. If we reserve the word "hearing" for what the ears do, and "the voice" for what the mouth speaks - not unreasonable, I think - then your question becomes, "How can I "hear" my "voice" when I'm not speaking?" i.e. "How can I undergo something which seems rather like hearing ("hear", in an extended or perhaps metaphorical sense) something which seems rather like my voice ("my voice", taken in an extended or perhaps metaphorical sense)? The important thing is to try to get clear about what the metaphors are metaphors on, if I can put it this way. ("The sun" is a metaphor on Juliet.) It is more than just imagination, because I can imagine a voice speaking, and hear it, without imagining that I hear it. That is, the minute the voice "speaks", I "hear" it, without an added act of imagination of the auditory (or rather, "atidory") kind. That is a puzzle: direct realism about inner "voices"! To the wider question, though, it is helpful to consider how astonishingly varied and numerous the metaphors are, even for one little subject. "He is de-spirited, rat-ty, a clown, a lounge lizard, a drag" and so on and on and on. Do we feel the "drag"? Do we feel the "rattiness"? Or do we judge it? Each of these metaphors trails its own distinctive cloud of epistemology. And so it is with the mind. Talk about the mind is often highly metaphorical, though not, on that account, by itself, false. If he is said to be ratty, the fact that we use a metaphor does not mean that what we mean is not true. Nor is it just metaphorically true, if this is taken to mean that "true" here is a metaphor.

A footnote here. The intent behind the act counts. But fantasizing and planning purely in the brainpan doesn't count as criminal. The closest the law comes is conspiring to commit a crime. Nonetheless, conspiracy calls for more than idle thought or even idle talk of the "Boy, wouldn't it be something to ..." sort.

We do give moral credit for overcoming serious temptation. But deliberately indulging in wicked fantasies seems to be another matter. One reason is that we worry that people who do this regulalrly are more likely to succumb to the temptations that they induce in themselves. But another is that we value the character trait of being repulsed by the repulsive.