The usual story is roughly this. The quantifiers of a first-order logic (ordinary universal and existential quantifiers; or perhaps fancier dyadic quantifiers) range over objects in some given domain. A second-order logic, as well as having those first-order quantifiers, has quantifiers ranging over properties of those objects in the given domain -- or what may or may not come to the same thing, ranging over sets of objects from the domain. A third-order logic adds quantifiers ranging over properties of properties of things in the domain -- or what may or may not come to the same thing, ranging over sets of sets of objects from the domain. And so it goes. It's not for nothing, then, that people do often say, following Quine, that higher order logics are just fragments of set theory in disguise. But be that as it may. Where does e.g. propositional modal logic fall into the picture? Well, on the one hand, propositional modal logic has no quantifiers. So a fortiori it doesn't have first...

Is it worth exposing flaws in the reasoning for a position, even if you haven't something better to replace it with? Certainly. At the very least, revealing flaws ought to make proponents less dogmatic in their endorsing of the position: they should proceed with caution in trying to implement policies based on the position, not close off the consideration of counter-proposals, etc. etc. All of which consquences are, in general, surely to be encouraged!

Insensitivity to suffering is indeed a bad thing. But Sally Haslanger's seeming implication that a willingness to kill animals and eat them requires insensitivity to suffering is highly contentious. I might happily go out of a late evening with gun and dog to get a rabbit for the pot (good sustainable food, and the proliferating beasts are bit of a pest, even with the foxes, buzzards, stoats and even local cats very busily doing their bit). Maybe that shows I'm not at all sentimental about about the bunnikins of children's story books, but must it show insensitivity to suffering? Why so? On the contrary, I take a gun which will give a clean kill, I'll put a sick animal out of its misery, and so forth. On the common land that runs almost into the centre of Cambridge, handsome Red Poll cattle are now raised by the local vet exercising her ancient commoner's rights as a local resident (sustainably using grazing that would otherwise go to waste). They are very well looked after and then locally and...

Another hint (and a rather shorter read!!): the opening pages of To mock a mockingbird and other logic puzzles by Raymond M. Smullyan. I couldn't possibly recommend looking via Google Books. :-)

"But love is blind and lovers cannot see/The pretty follies that themselves commit", as Jessica says in the Merchant of Venice. "But if thy love were ever like to mine/How many actions most ridiculous/Hast thou been drawn to by thy fantasy?" Silvius remarks in As You Like It . Oh yes, love can make you foolish. It may be sublime, but it can grip us in the most inapposite ways. Even proud Titania falls for Bottom with his head turned into that of an ass (so much for physical appearance!). Such is the way of it. But does it make romantic love any the less wonderful that it is all rather arbitrary, depends on the happenstance of a meeting and the chemistry of an underlying physical attraction, and makes us a little bit mad? I don't see why! Why shouldn't we place a high value on love -- find it "sublime" though also delightfully human -- even if it is the result of such earthly accidents? After all, an Alpine landscape is thrown up by an underlying clash of tectonic plates and sculpted by the...

Suppose you and an enthusiastic partner have fun getting very imaginative with your video camera. Then after the event -- your partner away for a while, and with their encouragement -- you amuse yourself watching the results, and thereby "consume" what are pornographic materials (here taking pornography to be "the representation in books, magazines, photographs, films, and other media of scenes of sexual behavior that are erotic or lewd and are designed to arouse sexual interest"). It is very difficult to see why you should have any moral qualms about this. Suppose on the other hand you search the sleazier end of the internet to find illegal child pornography. It is very easy to see why you should have more than mere qualms about that . So -- fairly uncontentiously, I hope! -- it all depends on the type of materials, and there can't be a straight yes/no answer to the question asked. The tough question is different: where are the moral lines to be drawn?

Let me recycle the answer I gave to an earlier question . It is indeed a truism that, when I act, it is as a result of my desires, my intentions, my goals. After all, if my arm moves independently of my desires, e.g. because you want it to move and push it, then we'd hardly say that the movement was my action (it was something that happened to my body despite my desires). But even if everything I genuinely do (as opposed to undergo) is as a result of my desires etc., it doesn't follow that everything I do has a selfish or egoistic motive. For to say that I do something for a selfish reason is to say something about the content of my desires (it is to say something about what it is I desire). In other words, to say that I act on a selfish desire it is to say not just that the desire is mine but that the desire is about me or directed towards me or something like that. And it is just false that all my desires are like that. I can want to bring about states of affairs in which I...

Well, yes of course, two incompetent reasoners could reach different conclusions by making different mistakes! So I take it the question is: could two people reason correctly to different conclusions from the same premisses? But again the answer to that is, trivially, "yes". A given bunch of premisses will entail lots of conclusions (e.g. the axioms of Euclidean geometry entail both that the angles of a triangle add up to two right angles, and that the tangent at the point on a circle is at a right angle to the diameter through that point). One reasoner can correctly deduce one conclusion; another reasoner can correctly deduce a different conclusion. Still, in that case, the different conclusions are all consistent with each other. So perhaps the question is supposed to be: can two two people reason correctly from the same premisses to conclusions that are "different" in the strong sense of being actually incompatible with each other? Again, the answer to that is obviously "yes". For...

Jennifer Church points out a couple of types of a case where irrationally formed beliefs (or degrees of belief, in the over-confidence case) can promote our welfare. Sure there are such cases. But that doesn't affect the original point at stake. There being a few cases doesn't undermine the point that in general false beliefs (because of their content!) are unlikely to lead to successful action,* and so irrationally formed beliefs -- being likely to be false -- are not in general likely to lead to actions which get us what we want. And that is enough to explain why we should in general care a lot about forming our beliefs in a rational way. Which in turnis enough to counter the original questioner's worry that philosophy"uses as its main tool a mechanism [rational thought] that is theopposite of what is most important to us": in general ,rational belief-formation matters for getting whatever is important tous. *Indeed, some attractive views about ascribing content to belief...

Mitch and I posted our responses simultaneously! I agree very much with his ... I'm not sure it is true that most philosophers talk in a way incomprehensible to non-professionals -- at least when they are trying to address them! After all, there are many, many, dozens of well-written, accessible, thoroughly readable books by philosophers written for beginners. And even if books by philosophers written for other philosophers are difficult to understand, that isn't usually a matter of the language used: the trouble is more that the books tend to contributions to long-running debates, and if you don't know the background you probably won't grasp the point of what's being said. As to 'the': why do philosophers of logic and language want to know how "definite descriptions" like "the present Queen of England", "the tallest man", "the woman in the corner drinking a martini" work? Well, it's part of a larger project -- understanding the way referring expressions of various kinds...