On 'Cogito Ergo Sum' If this statement means that the only thing I can know to be true is that I exist, then that means I don't know if the reasoning used to deduce this statement is logically sound. What evidence do we have that our reasoning is to be believed? The only reason that we trust our reasoning is because have reasoned that it is trustworthy. We trust our reasoning because we trust our reasoning. I know that I came to this conclusion with the same human logic as cogito ergo sum, so this conclusion must be equally invalid. Humans are imperfect-> humans 'invented' logic-> logic is not necessarily perfect. "I do not know if I know anything." Please fix any broken logic I have, or point me in the direction of relevant articles on how my thinking was outdone hundreds of years ago. Thanks

I think I could do little better than to point you to what Descartes himself says about this. It's quite right that, in the First Meditation, he does seem to bring even logical (or mathematical) reasoning into the scope of his sceptical doubt: "What is more, since sometimes I believe that others go astray in cases where they think they have the most perfect knowledge, may I not similarly go wrong every time I add two and three or count the sides of a square, or in some even simpler matter, if that is imaginable?" (CSM II, 14; AT VII, 21). And then, at the start of the Second Meditation, we get the Cogito which, on the face of it, certainly seems to have the form of a logical deduction of existence from thought. So is he really entitled to it at all? Couldn't he similarly go wrong there too? Well, Descartes would say no, and the clue to his solution is to be found in the Second Replies: "when we become aware that we are thinking things, this is a primary notion which is not derived by means of...

I want to say Hume was an idealist but this seems controversial. My reasoning goes like this. Hume thinks that all we can know comes from our personal experience (this is uncontroversial Hume was an empiricist). He also thinks that we have no justification for believing in an external world, because all we ever experience are our sense perceptions which, Hume thinks, are wholly mind dependent. So Hume thinks all we can know is mind dependent and we have no justification for believing that there is anything more than this. So for Hume all there is, is mind dependent stuff. This clearly makes Hume an idealist. So my qustion is am I right in saying that Hume was an idealist?

It's quite true that Hume uses psychological terminology when setting out his position, even to the point of using the term 'idea' itself (alongside 'impression'). So, simply taken at face value, I'd agree that he does come across as a bit of an idealist. Nevertheless, probing more deeply, I would still want to resist that conclusion. For, the terminology notwithstanding, where I would be most inclined to take issue with your summary is in the claim that he regards these perceptions as being "wholly mind dependent". For something to be mind-dependent, I take it, the suggestion is that it couldn't exist without a mind. That certainly how a clear-cut idealist like Berkeley uses the term. But let's remember what Hume thinks the mind actually amounts to. It is, he says, "nothing but a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in a perpetual flux and movement" ( Treatise 1.4.6). So any given perception will be existing in a mind,...

Why did Descartes pick thinking of all possible attributes to logically establish existence? Rocks exist but don't think. What exactly did he have in mind to establish? Was it really existence? Did he have any valid reason to doubt his or our existence? Wouldn't pain be a better criterion? Or movement? Or change? If a non-philosopher raised such a question we would certainly look askance at him and not value his "evidence" either way.

The first thing to observe is that Descartes felt that the notion of 'unconscious thought' was incoherent. Maybe there can be neurological processes going on in the brain that we're not conscious of -- he would have no quarrel with that -- but, simply in virtue of the fact that there's no consciousness involved in the case, he would deny to these the title of 'thoughts'. If something is going to qualify as a thought at all, it needs to be a conscious thought. But then, what does 'conscious' mean? It means that these thoughts, when I have them, are accompanied by knowledge. And knowledge of what? Of the fact that I'm having them. "But", writes Descartes in the Second Meditation, "I do not yet have a sufficient understanding of what this 'I' is, that now necessarily exists." It's very easy to show that something exists: for, as soon as we think, we have this conscious awareness of the fact. But what exists? Answer: a thinking thing! And so that is what Descartes takes the pronoun 'I' to refer...

Aha! My answer seems to have crossed in the mail, as it were, with Charles Taliaferro's. Well, there you go, two for the price of one! The price, of course, being free: isn't this a lovely site?

I have a question regarding referencing and I don't know where else to turn, the quote: " Our greatest weapon against stress is our ability to choose one thought over another" is all over the net attributed to James, but I can not find a specific work of his which it is cited. Can anyone help?

That definitely doesn't sound like William James, on account of the use of the word "stress". The notion of stress, in what I take to be the relevant sense of the term, only really started to arise in the 1950s. But James died in 1910. That's the internet for you. He did however say the following, which might perhaps have inspired whoever it was that made up that quotation: "The great thing, then, in all education, is to make our nervous system our ally instead of our enemy . It is to fund and capitalize our acquisitions, and live at ease upon the interest of the fund. For this we must make automatic and habitual, as early as possible, as many useful actions as we can , and guard against the growing into ways that are likely to be disadvantageous to us, as we should guard against the plague. The more of the details of our daily life we can hand over to the effortless custody of automatism, the more our higher powers of mind will be set free for their own proper work. There is no more...

Did Hume commit the genetic fallacy when he argued that one of the reasons we should not believe in miracles was because they derived from "ignorant and barbarous nations"?

Before I address your question directly, it would be worth just running through Hume's main argument in section 10 of the Enquiry concerning Human Understanding , for the sake of those readers who might not have come across it before. Hume is concerned with the credibility of testimony concerning miracles. When we receive such testimony (in any form, whether received orally from one of our own contemporaries, or read in an ancient book), Hume asks us to weigh up the credibility of two competing hypotheses. (1) That the testimony is true, the laws of nature were violated, and the miracle really did occur as described. (Hume regards the violation of the laws of nature as being an essential, defining feature of a miracle. Others would define 'miracle' in other ways, and Hume's argument might not apply to them: but he is concerned with miracles as he defines the term). (2) That the testimony is false (whether through deliberate deceit or just through honest error), the laws of nature were not...

Descartes's argument: ''I think, therefore, I exist'' is an ontological argument? If Descartes said that It is, if he did (?), where (book) he says it? Thank you very much.

No, Descartes never called it an ontological argument. He wouldn't even have known what such a claim was supposed to mean, because the expression simply didn't exist in his time. The term 'ontological argument' was introduced (or at least popularised) by Immanuel Kant, more than a century after Descartes died. But would Kant, at least, have called it an ontological argument? No, because Kant -- and effectively everyone else who's used the term since him -- opted to use that term to denote a certain class of arguments for the existence of God, specifically, and Descartes (by his own admission!) was not God. So let's just put the terminology to one side: it's never a good idea to allow oneself to get hung up on jargon, when what we should really be looking at is the argument itself. Perhaps a better question to ask is this: does Descartes' "I think, therefore I exist" at least have a structure analogous to that which we find in those arguments for the existence of God that philosophers since Kant have...

Is it appropriate for philosophers who specialize in specific branches of philosophy to comment on philosophical branches outside their field of training? By analogy, a professional chemist would almost never publish books or articles in computer science. Why then should we even consider the political theories of Noam Chomsky (a linguist and philosopher of language) instead of those of Machiavelli or Leo Strauss? Or the moral writings of Bertrand Russell (a logician and philosopher of science)?

First, let's consider what constitutes 'training'. Should we, for instance, be focusing solely on the subject(s) in which someone has taken a formal degree? It's true that Chomsky didn't formally study politics as either an undergraduate or a doctoral student: but then, neither did Machiavelli or Strauss. And Locke started out in medicine, Wittgenstein started out in engineering, David Lewis started out in chemistry, and, yes, Russell started out in mathematics. And so on. If we're going to dismiss them from the philosophical canon on those grounds alone, then we'd be losing an awful lot. What's more, if this was going to be our touchstone, then the career of any academic would be decidedly short: after ten or twenty years, their own field will have moved on from how it was when they first studied it, thereby rendering them ineligible to carry on working in it, at least without taking a second degree as a refresher course. But that would be a silly conclusion to draw. Better, I'd have thought, to...

Can space be cognized by only verbal means or does it require experience to be understood? Let me show you what I am getting at. You could never imagine what the color red is from a description of it and I think most people see that as an intrinsic limitation on language. No matter how sophisticated the person listening/describing or how sophisticated the language used you would never know what red is without an experience of it. Is space equally ineffable when it comes to descriptions of it?

Imagine there's a pure, disembodied intellect, and you somehow have the ability to communicate with it. It's a very clever intellect, so it's perfectly receptive to abstract, a priori mathematics: but it has never had any experience of spatial things, and it wants you to explain space to it. How might you go about this? Well, first you might explain the number line. You invite it to consider an infinite set of objects (we'll call them 'real numbers'), all different from one another, but continuously ordered in two directions from a particular element that we'll call 'zero' (or 'the origin'): ever greater to a positive infinity, and ever less to a negative infinity. And now, with the number line in place, you invite the intellect to take three such lines. That is to say, you invite it to consider an infinity of ordered triples of the form <x, y, z>, where x, y and z are all real numbers from this same set, but are capable of varying independently of one another. Let's call each of these triples a ...

Dear Philosophers, I'm currently reading an excerpt from Descartes' Meditations, specifically the part where he attempts to prove the existence of god. I found myself unable to properly understand his notions of 'formal' reality or truth as compared to 'objective' reality or truth. The fact that an idea appears to him as something specifically, does not mean that it IS that something in reality (it might be merely appearance). However, taken purely in itself, at least the mental representation of the idea is real. Is the former here what Descartes continues to denote with 'objective' reality and the latter 'former' reality, or the other way around? Every time I think I have it figured out what these two terms mean, he uses them in a confusing manner two sentences later. Please help! Sadly, I'm reading an (undoubtedly terrible) translation which does not contain original page numbers; I hope you are able to answer my question without these as reference! Thanks in advance, and with regards, Paul

'Formal' reality is a measure of the amount of perfection a thing actually has. Every existing thing has some formal reality, and the quantity of this reality depends on the kind of thing it is. (Putting it in traditional -- though not altogether Cartesian -- terms, it depends on its form ). God, if he exists at all, will have infinite formal reality, because the essence of God is to be an infinitely perfect being. Created substances will have considerably less formal reality than God, because it is in their nature to be contingent, dependent beings, limited and temporal, all of which connotes a degree of imperfection. And modes of those substances will have less still, because they are dependent not only on God but also on the substances whose modes they are. 'Objective' reality, meanwhile, only pertains to certain kinds of thing, namely those that have representational content. This might be a physical representation, e.g. a painting or a verbal description; or it might be a mental...

do you think that there are certain knowledge that cannot be attained thru logic, and could only be attained thru other means like that of a meditation?

To begin with a slightly pedantic point: logic doesn't actually give us very much knowledge at all. Logic tells us things like that, if A is true and B is true, then A & B is true. But, in order for us to be in a position to draw that conclusion, we first need to know that A is true and B is true. And, for most ordinary A s and B s, logic isn't going to tell us that. We need to turn instead to our senses. We have five external senses -- sight, touch, hearing, smell, taste -- which tell us about the qualities of objects in our environment. And, if we use these in a cautious and regimented way, and maybe start to draw logical inferences once we do first have the raw data to work from, then we can achieve an awful lot of knowledge. But now to turn to your question: can meditation give us additional knowledge, besides that which we can get through the external senses? Yes, it surely can. Meditation can teach us what it feels like to meditate. Indeed, it might enable us to...

Pages