Knowledge and Belief
• People can believe things that aren’t true.
• For you to know something, it must be true and you must believe it.
• Beliefs can be true or false.
• Beliefs can accidentally be true, but it isn’t knowledge.
Types of Knowledge
• Analytic – true by definition – “Squares have 4 sides”.
• Synthetic – not analytic, true or false in the way the word is – “Ripe tomatoes are red”.
• A priori – doesn’t require sense experience to know – “all bachelors are unmarried”.
• A posteriori – can be established through sense experience – “Snow is white”.
All Analytic propositions are known a priori. This doesn’t mean that all a priori propositions are analytic. The main question is “Are all synthetic propositions a posteriori?” i.e; do we have some knowledge that doesn’t come from sense experience? It is this question that forms the debate between rationalism and empiricism.
Rationalism vs. Empiricism
• Main dividing questions are: “What are the sources of knowledge?”, “How do we acquire it?”, “How do we get concepts?”.
• Rationalism gives an important role to reason.
• Empiricism gives an important role to the senses.
• Why can’t we use both in acquiring knowledge?
• Rationalism claims that we can have synthetic a priori knowledge of the external world. Empiricism denies this.
• Rationalists argue that it’s possible for us to know some synthetic propositions about the world outside our own minds, e.g. Maths and morality. Empiricists argue that it is not.
• Both rationalists and empiricists accept that we naturally have certain thoughts and feelings inside our minds.
• An advantage of empiricism is that it allows us to quickly see how we ascertain our knowledge – through our senses by perceiving how the world is, which is a causal process – it requires no mental reasoning.
• Empiricists also claim that this is how we acquire our concepts – through our senses.
• Once we understand the acquired concepts, we gain analytic knowledge.
If we have knowledge that doesn’t come from sense experience – how do we get this knowledge? Rationalists argue that we either gain this knowledge from ‘rational intuition’ or ‘insight’, which allows us to gain this knowledge intellectually, or we just know these truths innately as part of our rational nature. Rationalists may also argue that some, or even all of our concepts are innate of come from rational insight.
Do All Ideas Derive From Sense Experience?
John Locke – Mind as a ‘Tabula Rasa’
• Locke argues that all ideas derive from sense experience.
• He says that the mind at birth is a ‘tabula rasa’ – a blank slate that gets filled up with ideas from the senses.
• He refutes the claim of ‘innate ideas’.
• Ideas can either be part of a proposition: “He had the idea that it would be fun to take the day off”; or they can be concepts: “the idea of yellow”.
• Locke says that all our concepts derive from sense experience, and that we have no knowledge prior to sense experience.
From Locke’s definition of ‘innate idea’, it follows that everyone with a mind should have the same ideas. However, there is no truth that every person (including people lacking reasoning skills) can assent and agree to.
So perhaps, with Locke’s definition, innate ideas are ones that we known as soon as we gain the use of reason. Locke refutes this, saying that we aren’t lacking reason but the knowledge of ideas.
For example, a child can’t know that “4 + 5 = 9” until the child can count up to 9 and has the idea of equality. It is the same thing as knowing that an apple is not a stick – it’s not a development of reason, just the gaining of knowledge of ideas.
So therefore, if we must first acquire the concepts involved (through sense...