In Defense of Pure Reason : A Rationalist Account of A Priori Justification (Cambridge Studies in Philosophy)

Rating:
Summary: A defense of moderate rationalism
Review: Bonjour is more successful than most in presenting a sensible account of a priori knowledge, but ultimately, like all rationalists, he leaves the final answer shrouded in mystery. His negative arguments against the power of non-rationalist theories are very cogent. Unfortunately, he fails to show that his own position is on sturdier ground.

That said, Bonjour is one of the clearest writers in epistemology, and I am comfortable recommending this book to anyone interested in the field. The negative arguments about induction, particularly, are very well presented.

Rating:
Summary: A defense of moderate rationalism
Review: Bonjour is more successful than most in presenting a sensible account of a priori knowledge, but ultimately, like all rationalists, he leaves the final answer shrouded in mystery. His negative arguments against the power of non-rationalist theories are very cogent. Unfortunately, he fails to show that his own position is on sturdier ground.

That said, Bonjour is one of the clearest writers in epistemology, and I am comfortable recommending this book to anyone interested in the field. The negative arguments about induction, particularly, are very well presented.

Rating:
Summary: Interesting but it conflicts with reality.
Review: I have not read all the book but noticed in the propositions assumed as reliable, for example that something cannot be "red all over and green all over", that this has turned out not to be correct as determined by science. Investigations into the nature of our physical universe has given us the strange conclusion that a small subatomic particle such as an electron or a photon of light can indeed be "both red all over and green all over", e.g., be both a particle (a point) and a wave (extending indefinitely). This is not understandable to our reason but has been confirmed by experiment. Thus making the logical assumptions as given in the beginning of this book in conflict with what has been determined as the nature of reality and though it seems commonsense and logical to state that something cannot be in two states at once, it does seem indeed to be the way the world is constructed.

Rating:
Summary: Reason Vindicated
Review: Laurence BonJour has written an outstanding defense of "pure reason", i.e., the idea that the human mind can, by way of rational insight, arrive at certain truths about the nature of reality. These truths are known "a priori" and do not rely on the senses for their justification. The most obvious examples of a priori knowledge are the laws of logic and mathematics. Although certain a priori truths may have some empirical content (for example, the statement that something can't be all red and all green at the same time), even these truths are not justified on empirical grounds.

This view is, broadly speaking, called rationalism and is the dominant position in the history of philosophy. Not only was it advocated by explicit rationalists such as Plato, but also philosophers considered empiricists, such as Locke and Aristotle, were rationalists. It wasn't until Hume and his followers that rationalism went challenged. (Prof. BonJour has an interesting take on Kant, whom he places within the empiricist tradition.) In our day, rationalism has been defended by many distinguished (and diverse) philosophers such as Brand Blanshard, A. C. Ewing, Gordon Clark, and Roderick Chisolm.

Prof. BonJour elaborates on the standard rationalist argument that any attempt to build a rigorously empirical epistemology must ultimately depend on a priori insight. Take the above statement that something can't be all red and all green at the same time. How many examples of red and green objects would we have to observe to come to that conclusion? How would we know that we have made enough observations to be confident in our conclusion? In addition, how can we come to the conclusion given that nothing is entirely red or entirely green? As Brand Blanshard notes somewhere, even a not particularly bright person can cut to the heart of such matters by viewing just one object and applying his rather limited abilities of reflection.

Prof. BonJour's book is quite comprehensive and refutes many of the standard critiques of rationalism. In addition, he has a particularly devastating chapter on W.V.O Quine and his "naturalized epistemology." I highly recommend Prof. BonJour's other books, THE STRUCTURE OF EMPIRICAL KNOWLEDGE and EPISTEMOLOGY.

Rating:
Summary: Reason Vindicated
Review: Laurence BonJour has written an outstanding defense of "pure reason", i.e., the idea that the human mind can, by way of rational insight, arrive at certain truths about the nature of reality. These truths are known "a priori" and do not rely on the senses for their justification. The most obvious examples of a priori knowledge are the laws of logic and mathematics. Although certain a priori truths may have some empirical content (for example, the statement that something can't be all red and all green at the same time), even these truths are not justified on empirical grounds.

This view is, broadly speaking, called rationalism and is the dominant position in the history of philosophy. Not only was it advocated by explicit rationalists such as Plato, but also philosophers considered empiricists, such as Locke and Aristotle, were rationalists. It wasn't until Hume and his followers that rationalism went challenged. (Prof. BonJour has an interesting take on Kant, whom he places within the empiricist tradition.) In our day, rationalism has been defended by many distinguished (and diverse) philosophers such as Brand Blanshard, A. C. Ewing, Gordon Clark, and Roderick Chisolm.

Prof. BonJour elaborates on the standard rationalist argument that any attempt to build a rigorously empirical epistemology must ultimately depend on a priori insight. Take the above statement that something can't be all red and all green at the same time. How many examples of red and green objects would we have to observe to come to that conclusion? How would we know that we have made enough observations to be confident in our conclusion? In addition, how can we come to the conclusion given that nothing is entirely red or entirely green? As Brand Blanshard notes somewhere, even a not particularly bright person can cut to the heart of such matters by viewing just one object and applying his rather limited abilities of reflection.

Prof. BonJour's book is quite comprehensive and refutes many of the standard critiques of rationalism. In addition, he has a particularly devastating chapter on W.V.O Quine and his "naturalized epistemology." I highly recommend Prof. BonJour's other books, THE STRUCTURE OF EMPIRICAL KNOWLEDGE and EPISTEMOLOGY.

Rating:
Summary: An Incredible Book
Review: My only qualm with this book is that only a reader who has read some philosophy will find it truly accessible. It's length and scope doesn't allow the author to fully discuss many of the issues surrounding the topic of rational insight.

What is rational insight? One of the simplest examples is the syllogism: "All men are mortal. Socrates is a man. Socrates is mortal." Another example is the statement: "Something cannot be both green all over and red all over." I think that only the hardcore skeptic would deny the certainty of such insights. How do we justify/explain such insights? Here comes the rub - to justify such insights, the ability to grasp them must already be possessed by those who are justifying them and those to whom they must be justified. A point later defended by the author, and which has been defended by many rationalists, is that the structure of the world must such that these relationships are given in reality in some form.

Rather than list and categorize these insights, Bonjour mounts a wonderful defence for these insights, which he categorizes, like other rationalist philosophers, as "apriori" knowledge, or in his better term, "apriori justification". He, like other rationalists, describes them as a grasp of necessity: once thier nature is grasped and understood, people defend them by thinking and reasoning, rather than pointing to specific data given in experience.

The book has many wonderful points: a careful and reasoned exposition of why Kant was not a rationalist in the true sense of the word (this has been known to quite a few rationalists in the Aristotleian tradition, but Bonjour's criticism leaves little to the imagination), a defence of view of a priori knowledge as fallible, but fallible only in the sense that it answers to new and better apriori insights when found to be mistaken, and a nice and careful discussion of the major analytic school's objections against a priori knowledge.

A great part of this book is well made and much needed distinctions between the a priori and the a posteriori, the analytic and the synthetic, and the necessary and the contingent. His defence and qualification of these terms are worth the cost of the book alone, and he shows how misrepresentaions of these terms, and thier implications are, have led to the acceptance of weak arguments against them being considered conclusive rejections of them.

Finally, the author gives both the nice defence and the beginnings of an a priori theory of induction. The good thing about his defence is that it validates induction, and it will probably be easy to incorporate the best work that has been done into this field since I believe that Bonjour has silenced the greatest oppositions to induction as a source of knowledge.

It is a short book, and is quite limited in scope, but it was a page turner for me. I believe the influence of this book's arguments will be far reaching, once the required critical mass of intellectuals inculcate the ideas contained within this book.

I think my review is understated, so I will only say this: get the book if you have the philiosophical background, and be prepared for one of the best defences of Reason in philosophical history.

Rating:
Summary: An Incredible Book
Review: My only qualm with this book is that only a reader who has read some philosophy will find it truly accessible. It's length and scope doesn't allow the author to fully discuss many of the issues surrounding the topic of rational insight.

What is rational insight? One of the simplest examples is the syllogism: "All men are mortal. Socrates is a man. Socrates is mortal." Another example is the statement: "Something cannot be both green all over and red all over." I think that only the hardcore skeptic would deny the certainty of such insights. How do we justify/explain such insights? Here comes the rub - to justify such insights, the ability to grasp them must already be possessed by those who are justifying them and those to whom they must be justified. A point later defended by the author, and which has been defended by many rationalists, is that the structure of the world must such that these relationships are given in reality in some form.

Rather than list and categorize these insights, Bonjour mounts a wonderful defence for these insights, which he categorizes, like other rationalist philosophers, as "apriori" knowledge, or in his better term, "apriori justification". He, like other rationalists, describes them as a grasp of necessity: once thier nature is grasped and understood, people defend them by thinking and reasoning, rather than pointing to specific data given in experience.

The book has many wonderful points: a careful and reasoned exposition of why Kant was not a rationalist in the true sense of the word (this has been known to quite a few rationalists in the Aristotleian tradition, but Bonjour's criticism leaves little to the imagination), a defence of view of a priori knowledge as fallible, but fallible only in the sense that it answers to new and better apriori insights when found to be mistaken, and a nice and careful discussion of the major analytic school's objections against a priori knowledge.

A great part of this book is well made and much needed distinctions between the a priori and the a posteriori, the analytic and the synthetic, and the necessary and the contingent. His defence and qualification of these terms are worth the cost of the book alone, and he shows how misrepresentaions of these terms, and thier implications are, have led to the acceptance of weak arguments against them being considered conclusive rejections of them.

Finally, the author gives both the nice defence and the beginnings of an a priori theory of induction. The good thing about his defence is that it validates induction, and it will probably be easy to incorporate the best work that has been done into this field since I believe that Bonjour has silenced the greatest oppositions to induction as a source of knowledge.

It is a short book, and is quite limited in scope, but it was a page turner for me. I believe the influence of this book's arguments will be far reaching, once the required critical mass of intellectuals inculcate the ideas contained within this book.

I think my review is understated, so I will only say this: get the book if you have the philiosophical background, and be prepared for one of the best defences of Reason in philosophical history.

Rating:
Summary: A cogent defense of a priori justification
Review: One of the many minor joys of reading this marvelous book is seeing Kant toppled from his rationalist pedestal and pushed into the Humean camp, where he belongs.

But the major joy, as might be expected from the title, is watching BonJour develop a cogent defense of a priori justification.

In the process, he deftly turns aside the objections of empiricism, showing that empiricist accounts themselves depend on implicit use of the a priori.

And in what may be the most significant feature of his own positive account, BonJour acknowledges that a priori justification is _fallible_ but nevertheless cannot, strictly speaking, be refuted by experience; successful refutation always depends on a priori considerations.

Finally, BonJour closes with a promising start toward an a priori theory of induction.

This excellent and workmanlike book belongs on the shelf of anyone interested in understanding and defending the power of reason.