If the Sun were to explode we could not know of it until eight minutes later, because that is how long it takes for light to travel from the Sun to Earth. So for eight minutes we would see an unexploded Sun, while the real sun would be exploded. It follows that we do not see the real Sun. But everything we see must be later than reality, because of the time it takes light to travel from reality to our eyes, so nothing we see is real. Can this be true?

We do not see the sun as it is at the moment of our seeing ; but it certainly does not follow from this that we do not see the real sun. There are all kinds of delays, transformations and distortions of sensual evidence. This has led some philosophers (notably Descartes) to doubt whether sensual evidence can be relied upon to give an accurate 'picture' of how the world is. Descartes even went so far as to doubt whether things outside of him really existed at all. But the fact that I can doubt something is different from evidence for it not being real. Accordingly, Descartes did not argue that the general unreliability of sensual evidence had, as an implication, that what was sensed was not real. So, in your example, that the sun has ceased to be in the meantime (and therefore is no longer a real thing) is a problem about the reliability of our sensible knowledge in the present, but not a problem about the reality of what is sensed.

I have just been introduced to the works of Heidegger, and have been shocked by the way some commentators condemn his writings. Is such condemnation justified?

This is a larger question than it appears. It goes to the heart of what philosophy is or should be. That is, what methods should be employed, what standards or virtues of expression, language, analysis or argumentation, what subject matters are philosophical, and so forth. Heidegger is an important figure in what is sometimes called 'Continental' or 'European' philosophy. (Unfortunate names, but the ones most widely used). There are thousands of highly educated, widely published and read, and very distinguished philosophers who are working in this 'tradition'. Many of them disagree strongly with Heidegger, but at least take him seriously. However, there are, equally, thousands of philosophers of equal stature who either consider him to be incompetent as a philosopher, or just not philosophical at all. I cannot answer your question, therefore. I can only advise you to read commentators who condemn Heidegger, and likewise commentators who take him seriously, whilst bearing in mind that what is...

Can an ideal be achieved? If my understanding of what ideals are is correct (i.e., a mental conception regarded as a standard of perfection), then it seems that they are, by their very nature, unattainable (at least in a corporeal sense). Yet, nations are built, wars are fought, and people are killed over ideals. If they are only "perfect ideas", doesn't that seem a bit absurd and irrational? Is my understanding of what an "ideal" is incorrect?

In ordinary English, 'Ideal' has at least two meanings. One is an exemplar of perfection, as you say. E.g. an ideal professor, or an ideal partner. There seems no reason why this necessarily could not be attainable; that is to say, why such an object could not in fact exist. The other is a notion of a religious or moral nature that entails specific features that appear to be incompatible with the nature of existing things. So, for example, the ideal of an absolutely pure or selfless moral act. There are many plausible accounts of human nature (specifically of how human beings are motivated to act or make decisions) according to which this ideal is not possible. However, it seems to me that we misunderstand the nature of ideals if we focus on whether they are factually achievable or not. An ideal inaugurates a project of directed change. So, the ideal professor (assuming some measure of agreement of what that would be) directs real professors to improve their act. And this is true whether or...

To Whom it May Concern: Mathematical results are assumed to be precise. But how can mathematics be precise if results are rounded up or down? Don't such small incremental "roundings" add up to imprecision? So, in general, don't "roundings", in some way, betray the advertised precision of mathematics? Sincerely, Alexander

'Mathematics' covers a lot of ground: from pure geometry, for example, which is not quantitative at all -- that is to say, is not concerned with numbers and calculations -- to statistics which is not only quantitative but must do some version of the 'rounding' you speak of. Within statistics, however, part of the science (and in fact perhaps the most important part of the science!) is its ability to describe the imprecision of its results. For example, with the notion of a 'confidence interval'. This has two implications, it seems to me, one practical and one theoretical. First, the way in which statistical results are distributed through non-scientific forms of publication (reported in Newspapers, for example) often leaves out this analysis of precision, and every result is reported with equal confidence. This is not precisely a philosophical problem, to be sure, but certainly has implications for the ethics of the media, and for how scientific research is translated into political...

Today you can read a lot about ethical and unethical doing and specially about companies that do act unethically or unfair. For a public person it's not always easy to determine if such accusations are righteous or not. My question: Is it unethical to invest in shares of companies, whose reputations are not that good because they are accused of repression of employees or groups (or supporting such repression), exploitation of nature and human, etc.?

An interesting and very timely question. It seems to me that it breaks down into several parts. First, we need to ignore the problem that what one person believes is unethical corporate behaviour another believes is appropriate competitive behaviour. For example, much of the current trend in ethical investing stems from religious groups, many of whom refuse to invest in companies that produce alcohol, as well as those that produce and sell arms to oppressive regimes. Many would for good reasons count the latter as a more important oversight than the latter. Let us assume that we are all agreed that behaviour X (using your example, treating the workforce in some particular way) is unethical. Second, your question assumes that if a company were in fact guilty of X, then that alone would preclude investment in it. However, corporate activities are complex; one might be inclined to take a holistic view of their activities and ignore one thing because of activities you feel are...

Is the question of whether God (or a god) can be posited as the 'designer' of the universe related in any way to the question of whether we can know anything about an author from studying their books?

The two questions you name are often taken to be analogous. The analogy is structured something like a designing God is to the designed universe as an author is to the book she writes . Accordingly, the history of such thoughts contains phrases such as 'the author of our being' or 'the book of nature'. Of course, the analogy need not be with a book, it could be any act of making: blacksmiths, potters (because of the 'clay' in Genesis), and so forth. Such an analogy is generally considered quite weak, depending upon anthropomorphic identifications. Your question, though, addresses a slightly different point. It is frequently argued by various literary theorists that the inference from a novel (say) to something about its author is invalid. Several schools of theorists make similar such points -- formalists, new critics, new historians, poststructuralists -- though for different reasons. It should be pointed out, however, that not all theorists of literature agree here. I doubt, for example,...

In relation to the debate raging in the US about evolution and Intelligent Design, I would like to know whether positing the existence and prior activity of an intelligent designer is a scientific or a philosophical question. Is it scientifically conceivable that the existence of a designer and of things having come about purposefully as opposed to randomly could ever be deduced from available or putative evidence?

If I may add one additional point to the ones already given: there is an all important difference between an intelligent designer that is a human being or an advanced alien civilisation, and an intelligent designer that is divine. The former could have evidence in its favour, and could be the object of scientific enquiry at least in principle . (We could in principle meet the aliens and ask them 'why did you make tigers?') The latter could not. The reason is contained in some of the arguments that Hume and Kant put forth against the classic arguments for the existence of a God. Namely, that the act of a divine being upon nature (a miracle) could not provide evidence for the being's divinity .

Is it sensible to think that time is more fundamental than space, because one can just close one's eyes and relive memories, going back in time or prospectively go forward in time to predict something, without actually changing your position in space?

The thesis that time is more fundamental than space is not uncommon among philosophers -- although the significance attached to this, and the meaning of 'fundamental' varies widely. At least arguably, Aristotle, Leibniz, Kant and Heidegger, are committed to some variety of this claim. Kant's argument has some similarities to yours. All propositions about things and events must, when fully analysed, include a subordinate proposition about time (if only the location in time of the act of thought itself). But not all propositions about things and events must include a subordinate proposition about space. Kant then uses this analysis to argue further that the basic categories of all thought must be understood to be rules for the determination of time relations.

What is the reasoning behind the existentialist claim that existence precedes essence?

Unfortunately, there is not one reasoning, since there are many different philosophers who have been called 'existentialists'. However, generally, the line of argument has to do with understanding the ontological differences between human beings and other types of beings. Other types of beings (a telephone, a piece of granite) may have essences -- definitions that determine the type of thing they are. And, there may be good reasons for thinking that a being cannot exist without an essence, without being the kind of thing that it is. (This is particularly clear in the case of manufactured entities.) However, there seems to be a difference with human beings. To be sure, all humans are of the type 'human', but morally and socially that doesn't tell us anything important about them. Instead, what seems most important to make up this human being's identity, to tell us what he or she is, are the sum total of that person's decisions. For that reason, existence precedes essence. In short, the...

Some years ago I heard one of the Beatles in the course of a conversation about his career opine that 'after all I might easily have been someone else, mightn't I'. I remember not being sure about this proposition. One half knows what is being got at but on the other hand, it seems barely intelligible. Could I easily have been someone else? Ian g

Well, not easily , or everyone would be doing it. This expression might mean one of several things. Here are just three possibilities: (1) That the person I am, what has happened to me, seems accidental, a result of small 'twists of fate' which, my experience of similar events tells me, could 'easily' have turned out differently. The implication might be that the particular identity we happen to have is fragile and to some extent out of our control. (2) That I do not deserve to be who I am or have what I have; that there is no moral reason or principle of justice by means of which I deserve all this. This raises an interesting question in ethical and political thought: to what extent is it just to allow someone to profit from their luck, or even from their talent (or suffer their bad luck or lack of talent)? 'Luck' and 'Talent' are defined as good or bad things that happen do you that are out of your control and not a result of the decisions you have made. (A system of the partial redistribution...

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