The Great Conversation:
Knowledge

Writing about knowledge is a tricky business: everything we either write or read has something to do with knowledge, but satisfactorily defining knowledge seems almost impossible—just as everything we see has something to do with light and yet looking directly at the sun is not a good idea. Nonetheless, and for various reasons, knowledge remains one of the perennial topics of the Great Conversation as conducted by philosophers, judges, scientists, historians, and theologians.

Defining what constitutes knowledge was, according to his most illustrious pupil, the chief interest of Socrates. Many of Plato‘s dialogues, especially earlier ones such as the Meno and the Protagoras, are concerned with how we learn and with what can be taught versus what cannot. The Theætatus deals entirely with the subject of knowledge, and it is from this that we get the traditional definition that knowledge is “justified true belief,” i.e. an opinion held by somebody about a topic, for reasons that are adequate for them to consider this not merely a guess but a fact, and which is also actually correct. We lack space here to explain Plato’s reasoning, but it is interesting that the long success this definition has enjoyed is rather ironic given its source: the Theætatus discusses this as well as two further definitions of knowledge, and finds all three unsatisfactory! Despite our modern association of Platonism with the radiance of the Forms and the confidence that recollection of them supposedly affords, Plato’s Academy had a long tradition of skepticism after his death.

Aristotle had more confidence in the human intellect, and composed a collection of works entirely devoted to understanding and investigating statements, arguments, and fallacies of all kinds. Known collectively as the Organon, which roughly translates as “the Toolbox,” these works were a standard text on logical analysis for the Islamic Golden Age, European Scholasticism, and the Renaissance.

The issue of certainty tends to be the wedge that separates knowledge proper from opinion. A desire for certainty was what prompted Descartes to embark on his program of radical doubt, outlined in his Discourse on the Method. In order to escape from doubts, Descartes took the bull by the horns and decided to try doubting everything he could, in order to discover what doubt could not unsettle, and proceed from there to . Since he was there doing the doubting, the first un-doubtable thing he arrived at was his own existence; hence, of course, the famous line Cogito ergo sum, “I think, therefore I am.” From there, he reconstructed his whole intellectual universe, or at any rate one to his own satisfaction. This was the beginning of foundationalism, an approach to epistemology (the philosophy of how we know things) that attempts to place something beyond doubt, which can then in turn serve as the foundation for all other knowledge. Descartes saw logical inference as the best choice—a specific form of foundationalism called rationalism. Many European thinkers followed in his footsteps, whether they adopted his exact doctrines or not. In the British Isles, however, empiricism was more favored, this being the theory that sense experience rather than reason is the basis of knowledge. (A little ironically, thanks to his grand and intricate system of thought, both rationalists and empiricists could argue they were following Aristotle, if they wanted to claim him as an illustrious predecessor.)

A sort of hybrid of rationalism and empiricism that deserves note is a school of thought—perhaps more accurately an attitude—that’s sometimes called scientism. The attitude in question is that the scientific method is the best or only means of obtaining knowledge, and that things the scientific method does not address cannot be known (or, in extreme versions, cannot even exist). Not many actual scientists would make such a silly claim; they know, literally by experiment, that their fields of knowledge are changing and growing all the time, and that long-established beliefs are often overturned by new discoveries. Nonetheless, a scientistic attitude to knowledge can be discerned in many circles and contexts.