When are conditional statements actually true? I am getting contradicting answers. Please help. One resource, a geometry book, says that to prove a conditional statement true, you must show the conclusion is true every time the hypothesis is true. On the contrary, however, a discrete mathematics book says a conditional statement is true unless the hypothesis is true and the conclusion is false. These methods for checking the truth of a conditional statement do not produce the same results, however. For example, consider the conditional statement (1) If today is Saturday, then 5 + 5 = 6. Under the first method, this (1) is false, because when there is a time when the hypothesis is true (It is Saturday), but the conclusion is false (5 + 5 never equals 6). A counterexample exists, as they would say. But under the second method, the statement's truth value changes with time. It is true when it is not Saturday since the condition for falsehood, that it is Saturday and 5 + 5 does not equal 6, is...

You are confusing truth and logical validity. Your geometry book is writing about the logical validity of conditional arguments. Your math book is talking about the truth of conditional statements. Logical validity is much more than truth: it is truth that is independent of the truth or falsity of the premises.

I would like to ask if you feel it is contradictionary for chivalry to exist in a world where women push for equality. From a logical point of view a woman is perfectly capable of opening a door for herself and yet it is ingrained into society that men should open doors for women, the explanation for this being that it is polite, shows manners and shows you are a "gentleman". However I feel it is quite the opposite, if anything it promotes the idea that a woman is feeble and incapable of performing something as simple as opening a door. If a person had difficulty or was incapable of opening a door since I am performing for that person, what that person is incapable of. This makes sense. An even more extreme example is the romanticized idea of the man dying for the woman. If both men and women are equal shouldn't it really be every person for themselves in such a situation? Yet a man would be considered "weak" for allowing a woman to die when he could have saved her by sacrificing his own life in place of...

I think that you are right--in age of gender equality, opening doors for women, paying for them on dates, and definitely dying for them, seem to make little sense. Why, then, do these behaviors persist? In part, they persist because many people do not fully believe in gender equality. In addition, I think that some people just find it difficult to change their behavior for a variety of reasons, even when they believe in gender equality. My husband, for example, feels more well-mannered when he opens the door for a woman, and he likes that feeling (he was an Eagle Scout). (He prefers to be thought of as a little bit traditional than as a little bit inconsiderate.) As long as we treat women and men differently, gender equality will be a struggle. I ask my husband not to open doors for me--in practice taking turns opening doors seems to work best. We can all be more considerate of each other.

My father replaced the lenses on his glasses. Then he replaced the frame when it later broke. Same type of lenses and same model of frame. He claims they're still the same pair of glasses. When I argue he's wrong and that they're now a different pair, he claims the same could therefore be said of him as he's replaced all his cells several times since he originally bought the glasses but, since he's still him, the glasses are still the glasses. Who's right?

"Is the same as" is ambiguous. It could mean "same thing" or "same kind of thing" or even "same thing but not necessarily same stuff". Your father is speaking in the last sense--the glasses look the same, and moreover, the 3 pairs of glasses are built through successive fixes. You can avoid the verbal paradox by asking "the same in what respect?" The glasses are not the same stuff, and they do not have all the same physical properties (such as weaknesses in the glass and frame) but they are the same style and they are constructed successively out of one another.

Suppose someone brings John a glass of tap water, which John watcher being poured from an entirely normal tap. Yet suppose that the water from that particularly tap was somehow laced with poison. When asked what the glass contains, John, not knowing of the poison, says "That's water." Let's put aside the issue of whether witnessing tap water being poured is sufficient grounds for knowledge that the substance is in fact tap water, and assume that, were the water not poisoned, John would have a justified true belief about the contents of the glass. Presented with the poisoned water, does John have knowledge about the contents of the glass? I ask because, normally, our tap water contains a great deal of things besides water, yet we would not intuitively say that calling the stuff that comes from taps "water" is incorrect. But if some of the stuff was poison, it suddenly seems that John's belief that the glass contains water is incorrect (despite, in a sense, being obviously true), because if he were to...

Questions should be understood contextually. In your story about John, we are led to assume that John is about to drink the contents of the glass, and not, for example, use it in a chemistry experiment requiring high levels of purity. The suggestion is that it is water and not e.g. orange juice or beer. A small amount of harmless impurities don't make any difference to its drinkability-as-water. A tiny amount of cyanide, however, makes all the difference in the world to its drinkability-as-water. It's not the amount of impurity that matters, its the difference the impurity makes to our intended use of the water. (This is a case that shows the pragmatic functions of language. Sometimes you miss things if you take language "too literally" i.e. devoid of context.)

Is it ethical for psychologists and psychometricians to lie to their clients about their IQ if it protects them from harm to their self-esteem? I ask because I highly suspect that such a practice is both very common and something that has been practiced on me. I am told I have an IQ of a 138 which to me seems highly improbable given my academic record and my SAT scores, but I always wanted to join Mensa and I think i told my tester that. However when I applied for Mensa I had to have my records sent three times to their headquarters but each time they somehow got "lost" and so I never became an official member. It also seems improbable that so many people I have known have IQs higher than 150, it's like it's just very common for practitioners to give their clients high feel good numbers.

I think it is unethical for psychologists to lie to their clients about such test results. It would be best practice for a psychologist to ask their client why they want to take such a test and what they think the result means, as part of the process of consent for taking the test. Apparently this was not done in your case, and this is regrettable, since you seem to think that the test has great significance. A well known book you might enjoy is Howard Gardner's "Frames of Mind" which discerns seven different kinds of intelligence.

Is there any validity in the following argument? By medical science we keep people with severe chronical diseases alive and these people are free to reproduce. Already there has been an increase in people with chronical diseases, maybe because of our progression in medical science. So, in the future, it is possibly that we will all struggle with many chronical diseases, unless we accelerate in stem-cell research or genetic manipultaion. With this I see only two opportunities: either deny the chronically diseased to reproduce (Which I think is quite unethical) or "play God" and rid our selves with these plagues with either genetic manipulation or stem-cell research (which is also unethical, for some). But not matter what ethical principles one leans on, these two options are the only sensible ones, of course to the exception of not doing anything (which is also unethical). So we have here, three unethical options, depending on one´s ethical affiliation: 1. Everyone will be chronically diseased. 2....

We have been grappling with these ethical issues since the mid-nineteenth century and the beginning of the Eugenics movement. You have obviously done some deep thinking yourself, and perhaps it is time for you to engage with some texts in history and ethics in order to see how to take the questions further. I suggest Diane Paul's "Controlling Human Heredity" and "The Politics of Heredity" (both cheap paperback books) and an essay by Erik Parens "The Goodness of Fragility" widely reprinted in bioethics texts (there are many other bioethics resources, such as bioethics.net and http://bioethics.georgetown.edu/publications/scopenotes/

There was something that I wanted so badly for so long. Now, I got it but I am not as excited as I thought. How can we know what we want (our goal) in life?

Some recent papers by the psychologist Daniel Kahneman suggest that we are not very good at predicting what will make us happy. It is a good idea to read these to get a feel for human fallibility. Philosophers often argue that reflecting rationally on our values and goals can lead us to pursue what we "really" want, and thereby lead to greater satisfaction. You might try this and see whether it helps. Some Buddhists, and some psychologists, argue that pursuit of a goal is more exciting than achieving it. They suggest focussing on the activity rather than the desired result.

Some recent papers by the psychologist Daniel Kahneman suggest that we are not very good at predicting what will make us happy. It is a good idea to read these to get a feel for human fallibility. Philosophers often argue that reflecting rationally on our values and goals can lead us to pursue what we "really" want, and thereby lead to greater satisfaction. You might try this and see whether it helps. Some Buddhists, and some psychologists, argue that pursuit of a goal is more exciting than achieving it. They suggest focussing on the activity rather than the desired result.

How justified is a doctor's decision to practise cosmetics when he had sworn upon the Hippocratic Oath?

The Hippocratic Oath says a number of things, not all of which doctors swear to today (for example, the Hippocratic Oath forbids any kind of surgery). Perhaps you are thinking of the most well-known part of the Hippocratic Oath, that forbids harm. This is regularly interpreted as forbidding "unnecessary harm," e.g. vaccinations hurt, but they are a necessary harm to prevent a greater harm. Cosmetic surgery involves harm to the patient--the pain of surgery and the risks of surgery--so the question is, does it prevent a greater harm? The right people to ask about this is the people who undergo cosmetic surgery--both the ones with successful and the ones with unsuccessful results. They should be fully informed so as to balance the potential harms and benefits for themselves.

Are there any modern philosophers that still defend astrology as either a legitimate practice or as a science?

I don't know of any scientist who takes astrology seriously. There are two problems with astrology (1) the lack of confirmatory evidence and (2) the implausibility of the theory, given what else we know about the universe. But your question asked whether there are "modern philosophers" who take astrology seriously. Depending on how broadly the community of philosophers is defined, there may well be philosophers who take astrology seriously. You might be able to find a scientist or two, also. However, I doubt that there are scientists seriously working in the area of astrology (making predictions and testing them).

In this question, I'm going to assume there are strictly two human biological sexes, male and female. That assumption isn't exactly true (chromosomal variations), but it's a close enough approximation to ask the question. At restaurants such as "Hooters," provocatively-clad females serve food to patrons. There are no male waiters. No one seems to think too much about it. I think, however, that many people would be appalled if we had restaurants whose theme was to have provocatively-clad Jewish people serve food, or provocatively-clad African Americans serve food, or provocatively clad [insert religious or ethnic or national group] serve food. There are, of course, ethnic restaurants. So we might think of Hooters as nothing more and nothing less than another type of ethnic restaurant, this one peculiar to sex instead of ethnicity. Is this good reasoning? Maybe that reasoning is not valid. Women have a sex (female) and men have a sex (male). There can't be anything intrinsically more sexual about...

The questions that you are asking are terrific! They can also be taken further. E.g. is it necessary for you to assume that there are strictly two biological sexes? (I don't think so). Or e.g. What is wrong (if anything) with sexualization of a group? What is wrong with sexualization of a subordinate group? It is not difficult to turn up inconsistencies in what society considers to be socially normative.