How can the universe always be said to have existed, when there is nothing in the universe that always existed? People, plants, planets - all these things come into existence and then decay and disappear. In other words, every thing in the universe needs a cause for its existence. God, on the other hand, needs no such cause. This is not because he is "causa sui" or "self-caused"(an absurd notion, for how can something that has no being produce it own being?), but rather, he is "sine causa" or "WITHOUT a cause". Something, after all, always had to have existed. This is the Uncaused (call it God), not the Caused (Universe), which is inherently unstable and subject to flux. Scott from Ireland.

Cosmological Jeopardy: I'll answer your answers with questions... Why is it that something--or even just a multitude of strings of overlapping different things--needs always to have existed? Is it that it makes no sense to speak of existence if there are not particular things that do so? And even if we accept this claim, and that the existence of something(s)without a cause is the way to honor it, why does this thing (or things) need to be God and not the universe itself? Is the universe not particular enough?

Are people who have more imagination (or who use their imagination more) better people (more moral, cause less suffering, make better choices)? For example, I could argue that: - imagination leads to more empathy for others, more understanding of others points of view, more tolerance - imagination leads to creative solutions to problems (rather than punch the other guy in the face) - imagination allows a person to forsee the potential consequences of actions, and make less destructive choices - imagination stimulates thought, expression, variety, the artistic side of life which feeds the human spirit - imagination improves tolerance of others because a person is more comfortable with novelty and differences I often wonder if a certain kind of person or a specific person had had more imagination, would they have been a better person, or not have done something awful that they did. Saskatoon, Canada

To be plausible, all of your claims about imagination need to be qualified as "other things being equal", since there are, of course, examples of vivid imagination leading to terrible (and destructive and intolerant) actions. This said, I'm inclined to agree to most of the general claims you make for imagination. And in fact, we've just embarked our daughter on a Waldorf education that emphasizes the development of imagination, and all the benefits that this supposedly brings. However, to really assess all of this, we'd need a somewhat detailed account of what exactly counts as imagination (and greater or lesser amounts of it), and some tests to determine whether it links up in positive ways with the other properties you've identified. This task is partly philosophical, but mostly, I think, a matter for empirical psychology. It's an interesting topic, though. Sorry I don't have more to add.

Is it always the case that "two wrongs don't make a right"?

If two wrongs don't make a right, try a third. I think Nixon said that. But he wasn't the most reliable ethicist, and I can't think of a sitauation in which two wrongs would make a right. A just punishment might seem to come close, but doesn't really: the score may be settled when you've served your time, but your original crime isn't thereby made right (even though it's forgiven); and the sentence you served wasn't a second wrong anyway.

I know I feel very strongly about the importance of conserving biodiversity, but I really can't pin down why it is so important to me, or how to make the argument to convince others that it is important. Can philosophy help?

Philosophy might help in sifting through the possible reasons for conserving biodiversity--not just diversity of species, but also of types of ecosystems and also, perhaps, of genetic diversity within a species. And what is worrying about our current situation, by the way, is not simply that species are going extinct (this has always happened), but that diversity is disappearing at an alarming rate and on an alarming scale--one that is perhaps comparable to the five or so mass extinctions that have taken place over the past 440 million years. And we seem to be causing it! There are surely a number of very good instrumental reasons for preserving biodiversity. First, in biodiversity lies a treasure chest of potential medicines, foods, and other things that might be useful to us. Second, we don't want to lose clues to a more complete understanding of the workings and history of the Earth. Third, for many of us, even non-religious types, the diversity of life is a deep and awesome source of aesthetic and...

I read an article in Scientific American magazine discussing the existence of parts of the brain that regulate awareness of the self. Part of the article examined the damage or destruction of these neurological pathways through diseases like Alzheimer's. If it can be scientifically shown that the self ceases to exist in some Alzheimer's patients, what is left that walks, talks, thinks, and remembers? Is it a new self or a non-self or something totally different?

This is a good but difficult question. The answer, I think, depends upon what you mean by a "self". (Many people, including those who believe in immaterial, unified, and potentially disembodied "souls" would not agree that the notion of a "self" is open to several different, but equally useful characterizations.) If we require for the existence of a "self" the type of cognitive integration and global powers of rational understanding and planning that sadly break down in such patients, then, when the break down has gone too far, there remains no self in this sense. Nevertheless, there remains, of course, a body with all sorts of sophisticated abilities (to walk, to speak, etc.); and for all that I've said, there may remain a soul.

Is there such thing as true freedom? (My thought is that only in an anarchist society there would be-meaning that even the slightest rule or law would detain one's freedom to do as one pleases...)

Even in a world without laws or social rules, our ability to do exactly as we please would, presumably, be constrained by by all sorts of things--our own abilities, the actions of other people, gravity. (This won't be true, of course, if we could somehow adjust our desires so that we didn't want anything that we were constrained from having. But if we can do this, we might as easily do this in the world with laws.) In fact, the existence of rules and laws seems actually to allow us to do more of what we want. For example, the enforced convention that we drive on the right side of the road (in the US) allows us more efficiently and effectively to move about and do many of the things we want to do, even if it prohibits us from driving however we like with legal impunity. So, I doubt that anarchy would give us the "true freedom" you seek. But I wonder how much value we really place on "freedom" in this sense.

I was just discussing with a friend the concept of a perfect world. We were trying to define what would be a perfect world. I thought the perfect world would be world with a healthy balance of life and death, a healthy balance of war and peace, not enough food and not enough of other resources, and a healthy balance of one's own pain, and a world of distrust on top of that. But my friend seemed to hold a different view of it - a perfect world, to him, seemed to be one where there was always enough food, a world without death, a world with no war, and a world where you could go anywhere and trust every single person. We argued for a couple hours, but it was clear at one point that we had reached a stalemate. What do you guys think? What would be defined as a perfect world?

I have to say that from your description of the debate I'm inclined to side with your friend. His world contains a lot less suffering, and lot more human flourishing. You talk about a "healthy balance" of well-being and suffering. But why is this better than a world with very little or no suffering? Perhaps your idea is that some suffering is somehow needed in order to maximize human well-being. Is it that there needs to be some suffering so we can realize the well-being that comes from struggling towards and eventually achieveing something? Or is it that a world in which everything went perfectly would contain no background of even mild misfortune against which to appreciate our well-being as well-being. Such a world would be experienced as "flat", and almost dull in it's unwavering fortune. I'm skeptical of this, but in any case, the "healthy balance" of misfortune that might allow us to realize these greater forms of well-being would seem to require a lot less suffering than does our actual world. ...

What do philosophers mean by the term 'mental content'? My initial reaction to the phrase was to take it to mean something like 'the meaning of a thought, belief, etc.' But this interpretation seems...unexplanatory. It seems to me that things don't just MEAN; rather they mean TO some individual/group. (X doesn't just mean Y; X means Y to Z.) For any given thought/belief/whatever (X), we could imagine infinite different Zs, and through these Zs, infinite different Ys. Which Zs are the relevant ones? Why is whatever distinction is drawn between relevant and irrelevant Zs drawn as it is? Or is my vague conception of mental content as the meaning of a thought, belief, etc. not in line with how philosophers use the term? If so...what do they mean by it?

Although "mental content" is a term of art, and used in different ways by different philosophers, most take it to be the way--the proposition or information--that a mental state represents the world as being. My belief that Bush is president and my belief that Alaska is large differ in mental content--the first represents the world as containing a guy named "Bush" who is president, the second a large state called "Alaska". By contrast, my belief that it's sunny outside and my desire that it be sunny outside share the same mental content, though they constitute different attitudes towards this content. Even if this notion of mental content is clear enough, there are a number of important and unsettled issues surrounding it. One prominent issue is whether (and if so exactly how) the contents of our mental states are determined by features beyond the surface of our skin--most notably our environment and socio-linguistic setting. See for more on this....

If you go back in time and kill your former self, would it be suicide or murder? What if you went forward in time and killed your future self?

It's not clear that you can go back in time and kill your former self: a former self that doesn't get killed seems required for your presense at his side, contemplating the crime. This is a version of the grandfather paradox (you can travel back and talk to your own grandfather, but not kill him); though I should say that there are some (not me!) who hold that this type of thing is in fact made possible by a multi-verse interpretation of quantum mechanics. On the other hand, I don't see any impediments to using time-travel to kill off the final stage of yourself. (This needn't be in the relative chronological future if your life ends on a time-traveling adventure.) Whether it's suicide of merely murder seems purely terminological. It's "suicide" in one sense (you're done in by one of your own temporal stages), but not another (your final stage doesn't do itself in).