Knowledge Quotes

“In many fields—literature, music, architecture—the label ‘Modern’ stretches back to the early 20th century. Philosophy is odd in starting its Modern period almost 400 years earlier. This oddity is explained in large measure by a radical 16th century shift in our understanding of nature, a shift that also transformed our understanding of knowledge itself. On our Modern side of this line, thinkers as far back as Galileo Galilei (1564–1642) are engaged in research projects recognizably similar to our own. If we look back to the Pre-Modern era, we see something alien: this era features very different ways of thinking about how nature worked, and how it could be known.

To sample the strange flavour of pre-Modern thinking, try the following passage from the Renaissance thinker Paracelsus (1493–1541):

The whole world surrounds man as a circle surrounds one point. From this it follows that all things are related to this one point, no differently from an apple seed which is surrounded and preserved by the fruit … Everything that astronomical theory has profoundly fathomed by studying the planetary aspects and the stars … can also be applied to the firmament of the body.

Thinkers in this tradition took the universe to revolve around humanity, and sought to gain knowledge of nature by finding parallels between us and the heavens, seeing reality as a symbolic work of art composed with us in mind (see Figure 3).

By the 16th century, the idea that everything revolved around and reflected humanity was in danger, threatened by a number of unsettling discoveries, not least the proposal, advanced by Nicolaus Copernicus (1473–1543), that the earth was not actually at the centre of the universe. The old tradition struggled against the rise of the new. Faced with the news that Galileo’s telescopes had detected moons orbiting Jupiter, the traditionally minded scholar Francesco Sizzi argued that such observations were obviously mistaken. According to Sizzi, there could not possibly be more than seven ‘roving planets’ (or heavenly bodies other than the stars), given that there are seven holes in an animal’s head (two eyes, two ears, two nostrils and a mouth), seven metals, and seven days in a week.

Sizzi didn’t win that battle. It’s not just that we agree with Galileo that there are more than seven things moving around in the solar system. More fundamentally, we have a different way of thinking about nature and knowledge. We no longer expect there to be any special human significance to natural facts (‘Why seven planets as opposed to eight or 15?’) and we think knowledge will be gained by systematic and open-minded observations of nature rather than the sorts of analogies and patterns to which Sizzi appeals. However, the transition into the Modern era was not an easy one. The pattern-oriented ways of thinking characteristic of pre-Modern thought naturally appeal to meaning-hungry creatures like us. These ways of thinking are found in a great variety of cultures: in classical Chinese thought, for example, the five traditional elements (wood, water, fire, earth, and metal) are matched up with the five senses in a similar correspondence between the inner and the outer. As a further attraction, pre-Modern views often fit more smoothly with our everyday sense experience: naively, the earth looks to be stable and fixed while the sun moves across the sky, and it takes some serious discipline to convince oneself that the mathematically more simple models (like the sun-centred model of the solar system) are right.”
― Jennifer Nagel, Knowledge: A Very Short Introduction

“Philosopher Robert Cummins contends that we could only sort out which intuitions about knowledge were the right ones if we had some independent intuition-free access to the nature of knowledge itself. But if we had that kind of direct access we wouldn’t have to fumble with intuitions about particular cases to grasp the nature of knowledge: ‘If you know enough to start fixing problems with philosophical intuition, you already know enough to get along without it.’ Cummins concludes that philosophers should never rely on intuitions about cases in formulating theories of knowledge.”
― Jennifer Nagel, Knowledge: A Very Short Introduction

“The pattern-oriented ways of thinking characteristic of pre-Modern thought naturally appeal to meaning-hungry creatures like us. These ways of thinking are found in a great variety of cultures: in classical Chinese thought, for example, the five traditional elements (wood, water, fire, earth, and metal) are matched up with the five senses in a similar correspondence between the inner and the outer. As a further attraction, pre-Modern views often fit more smoothly with our everyday sense experience: naively, the earth looks to be stable and fixed while the sun moves across the sky, and it takes some serious discipline to convince oneself that the mathematically more simple models (like the sun-centred model of the solar system) are right.”
― Jennifer Nagel, Knowledge: A Very Short Introduction

“Oxford philosopher Timothy Williamson suggests that scepticism initially looks appealing (despite its bleak consequences) because it is a good thing carried too far. The good thing is that we have a healthy critical ability to double-check individual things we believe by suspending judgement in them temporarily to see whether they really fit with the rest of what we know. But if this ability to suspend individual beliefs serves as a useful immune system to weed out inconsistent and ungrounded ideas, scepticism is like an autoimmune disease in which the protective mechanism goes too far and attacks the healthy parts of the organism. Once we have suspended too much—for example, once we have brought into doubt the reality of the whole outer world—we no longer have the resources to reconfirm or support any of the perfectly reasonable things we believe.”
― Jennifer Nagel, Knowledge: A Very Short Introduction

“Academic sceptics argued for the conclusion that knowledge was impossible; Pyrrhonian sceptics aimed to reach no conclusions at all, suspending judgement on all questions, even the question of the possibility of knowledge.”
― Jennifer Nagel, Knowledge: A Very Short Introduction

“This sense of ‘knows’ has an interesting feature: there’s a word for it in all of the world’s 6,000+ human languages (‘think’ shares this feature). This status is surprisingly rare: an educated person has a vocabulary of about 20,000 words, but fewer than 100 of these are thought to have precise translations in every other language.”
― Jennifer Nagel, Knowledge: A Very Short Introduction

“Because impressions are always fallible, the Academic Sceptics argued, knowledge is impossible.”
― Jennifer Nagel, Knowledge: A Very Short Introduction