The importance of prior knowledge

A one line summary of Aristotle’s account of learning would be that we work things out from context. Aristotle starts Posterior Analytics by pointing out that everything we learn needs to relate to prior knowledge:

Otherwise, he says, we will end up stuck in the learner’s paradox that Plato described in Meno: if we try to find the answer to a question, how will we know we’ve found the right answer? If we don’t already know the answer then we won’t know whether we’ve found the answer, and if we do know the answer, then there’s nothing to learn.

According to Aristotle, however, we can generally tell whether or not an answer is the right one (or at least if it is the wrong one) because it will cohere with what we already know - it will fit into our web of knowledge. If someone tells me, for example, that Harold was shot with a bazooka at the battle of Hastings, I have enough background knowledge to know that this is not true. If someone shows me how to do a maths problem, I may suddenly see how the pieces fit together and say, ‘A-ha!’

A web of knowledge

Everything we know is connected to other things in a complex web, we just need to work out how - for Aristotle, the key to making those connections is in seeing what Categories different things belong to.

Imagine I say something like, ‘The Tata Altroz has four wheels’, you will immediately make an assumption about what a Tata Altroz is, even if you don’t know. You’ve probably already assumed that it’s a car, and if not at least some kind of road vehicle. This is because a car is the kind of thing that has four wheels.

Why is this the kind of thing we describe like that?

Aristotle thinks that to learn (and understand) something, we need to know how and why the subject of a sentence relates to the description of it. He suggests four key questions:

1. What kind of thing is this (the subject)

2. Does such a subject exist?

3. What kind of things can be described like that? (i.e. have that predicate)

4. Is the subject that kind of thing?

With the above example we’d answer the questions as follows:

1. What kind of thing is Tata Altroz?

   • It is a car

2. Is there such a thing as a Tata Altroz

   • Yes, look it up on the interwebs

3. What kind of thing can be described as having four wheels?

   • There are lots of different vehicles that have four wheels, normally land vehicles.

4. Is a Tata Altroz that kind of thing?

   • Yes! A car is a land vehicle.

Using Syllogisms to make connections

We can relate this back to Aristotle’s syllogisms:

1. A Tata Altroz is a car

2. Most cars have four wheels

3. ∴ A Tata Altroz most likely has four wheels.

So we can see that our original question fits into the three-term model of Aristotle’s syllogism:

Why is this (the subject) the kind of thing (the middle) that can be described like this (the predicate).

Now we can see what prior knowledge we need to learn something. Understanding is, according to Aristotle, made up of three things: Subject-middle/category-predicate. We need to know at least two of these in order to understand something new.

But how do we first learn things?

It is easy to see how Aristotle’s methods might work for learning and understanding new things in secondary school, but what about in primary school or even in nursery? Do we expect very small children to be able to connect terms together using categories? And if they can’t learn things like this, then how do we acquire the prior knowledge that we need to learn things in secondary school?

Aristotle has an answer to this. Strangely, Posterior Analytics is arranged backwards. It starts with the most advanced form of learning and then goes back to the most simple.

Three stages of learning

Aristotle says that learning proceeds in three stages:

1. Firstly, we learn to discern. We are born with innate powers of perception. We are able to distinguish between one thing and another. We don’t need to learn this as such, we do it instinctively. Think about how babies instinctively pick things up and shake them - in this way they learn to distinguish between one object and another. Aristotle calls this first stage Nous - or insight.

2. Secondly, we learn through induction. What this means is that we recognise that our words are tools, and we learn to use them to achieve our goals through trial and error. We learn that by shouting ‘Mama!’ we get the attention of our mother and so on. Aristotle calls this kind of knowledge techne - a craft or technical knowledge.

3. Thirdly, we start to build connections and understand why. This is the method of logical deduction described above. At this stage we begin to systemise our knowledge. At the age of about 3, young children begin to incessantly ask ‘why?’ to everything. This stage enables us to generalise the methods that we learn in the second inductive stage. The following analogy may help understand this. Imagine that someone has learnt to use a screwdriver in a particular situation - i.e. to tighten a particular screw. However, when they ask ‘why can I use this screwdriver to tighten this screw?’ they find out that the reason is because this is a flathead screw and this is a flathead screwdriver. Now they understand that they can not only use this screwdriver on this particular screw but also on other flathead screws - they have generalised their knowledge. Aristotle calls this kind of knowledge episteme - which is often translated as science, but is perhaps more like logic or understanding.