This site is written by me, John R. Josephson, as a way to work out some basic issues in epistemology (the philosophy of knowledge), and to develop material for a book to be entitled Knowledge Without Certainty. I hope for help from critical readers in the form of comments and discussion. Accordingly, I strongly invite constructive comments and discussion (see rules).
Specifically, I want to work out a theory of knowledge that encompasses both ordinary and scientific knowledge, knowledge of language and of how things work, knowledge from perception and from deliberation, conscious and unconscious knowledge, explicit and implicit knowledge, innate and learned, a priori and empirical, general and particular, discursive knowledge and intuitive grasp. This theory should clarify the nature of evidence, the logic of justification, and the logic of discovery.
I think a have stumbled upon an important key to understanding these things. That key is abductive inference, which I take to be Inference to the Best Explanation, and a part of “commonsense logic”.
I hope to develop a robust theory of knowledge that defends the possibility of real knowledge from various forms of skepticism, preserving it from being dismissed as merely opinion, or merely the propaganda of the rulers.
Related and relevant topics include: causal reasoning, cognition as computation, legal theory of evidence, information fusion, intelligence analysis, diagnosis, theory formation, and the foundations of science.
Knowledge without Certainty 
Dear jj,
Please define what you mean by knowledge? Inference to the best explanation does not lead to an understanding of consciousness, which occurs at birth! Inference to the best explanation is a good mechanism for a computer working out a fuzzy problem, but it cannot be (I don’t think) the root of everything we call knowledge. Did Haydn infer to the best hypothesis of what would make beautiful music?
When I see the first green of Spring, I know Spring is coming, but I already knew that. The pleasure I find in this knowledge isn’t inference to the best hypothesis, it is finding something in my brain, some memory that I want to experience and savor.
Nietzsche, albeit somewhat of a monster had this part right. We seek pleasure and thus we exist. Uncertainty is just the ants at the picnic.
“Please define what you mean by knowledge?”
I’m planning to work my way up to “Knowledge”, working my way through concepts of “Understanding”, “Truth”, “Inference”, and “Explanation”. But I’ll make a start, take a stab, write a draft, as follows:
“Knowledge” has several related meanings:
* True belief.
* True belief supported by evidence. This is similar to Plato’s definition of knowledge as justified true belief.
* Understanding. By this I mean (approximately) true belief about causal dependency supported by evidence.
* Grasp. By this I mean (approximately) understanding that empowers manipulation.
“Inference to the best explanation does not lead to an understanding of consciousness, which occurs at birth!”
Does anyone understand consciousness? If so, what is the structure of their understanding? Presumably, if they understand consciousness, they can explain how it arises, what it depends on. And how would they come to that understanding? What would be the nature of the evidence? Observations, imaginative hypotheses, and inference to the best explanation, I would think. I’m not suggesting that inference to the best explanation can account for consciousness, rather, that inference to the best explanation can account for knowledge.
“Inference to the best explanation is a good mechanism for a computer working out a fuzzy problem, but it cannot be (I don’t think) the root of everything … we call knowledge. Did Haydn infer to the best hypothesis of what would make beautiful music?”
Haydn presumably understood some things about making beautiful music, things about how melody, harmony, rhythm, etc. stimulate emotions and contribute to pleasing effects. Guided by those understandings, he could compose using trial and error, learning from experiments as he went. And how did he come to those understandings? What was the nature of the learning? Acquisition of knowledge using inference to the best explanation from observations and the results of experiments. I don’t see why not.
“When I see the first green of Spring, I know Spring is coming, but I already knew that. The pleasure I find in this knowledge isn’t inference to the best hypothesis, it is finding something in my brain, some memory that I want to experience and savor.”
If you hadn’t already known it, you could have inferred it (by IBE) from the appearing of the green things. If you already knew, you would have new evidence, plus a pleasant reminder. The pleasure comes, probably not from the inferring, but from the anticipation of spring.
Tom, Thanks for your comments!