Some things you know as part of your existence, and provide a building block for further knowledge. Yet if these a priori truths exist, why isn't it obvious what they are? After all, Philosophers still can't agree what are reasonable axioms for philosophising.
The answer sheds light on why Philosophers don't agree on anything, and the current limits of Philosophy.
[a priori = knowledge gained from your existing. The truth of it is part of your existing. For instance, the colour 'red' is there in your eyesight. You cannot deny it being there, although you might dispute where the 'redness' came from]
The first possibility is a language issue. Language which has developed and adapted for things such as 'there is a lion over there' or 'pass me the food' may not be good for Philosophy.
In particular, a priori truths refer to fundamental facts of existence. When referring to fundamental emotions such as 'pain', language does a pretty good job. This is hardly surprising, as these concepts are very important to communicate - although even here pain can refer to many things and language fails to fully capture what we mean.
Concepts such as truth remain much more elusive. Again, within a social group, there is normally a broadly similar idea of what truth is. For instance, when you talk to friends you don't get stuck defining truth when they ask you what you had for dinner last night. Across social groups, this can vary - for instance a group of Christians and a group of Buddhists might have quite a different conception of what constitutes truth in a spiritual/religious context.
When I read the word truth I understand it, even if I cannot put my finger down on what it is. Here lies the issue. There are certain concepts which I cannot explain to others whatsoever without assuming they already understand it. Try explaining colour to a blind man who has never seen - I cannot 'explain' the colour red in any meaningful way to him. Similarly, could you explain 'truth' without merely using synonyms?
So, these basic concepts give us trouble because we cannot express what they are too others. If the other person lacks these experiences we are stuck.
Unmixing a cocktail
So, we have a language problem. When we say a word such as 'truth' we reference a concept which we simply assume the other person has a similar understanding of. We might realise they are using the word in a different way and guess how they use it by thinking what you would do in a situation (and thus assume similar experiences). Nevertheless, you lack the ability to directly access what they understand by the concept.
This causes difficulty. Our emotions and experiences are complicated cocktails, and when we reference part of them with a word we want the other person to know what we mean.
Yet with the most fundamental concepts and experiences, the words 'splurge'. They may have subtly different connections and meanings to individual people, which are hard to correct. Providing definitions for fundamental concepts fails to help much as they end up being self-referential. Assuming some similarity in experience, the largest discrepancies are spotted but there is way to see if exactly the same concepts are harnessed when a word is used.
This means that arguments end up meaning different things to different people, and persuasion and verification is difficult.
Let's look at the 'Kalam Cosmological Argument' for the existence of God. (There are later steps which look at the nature of whatever was the cause of the Universe but I won't look at them now)
- Whatever begins to exist has a cause.
- The Universe began to exist.
- Therefore, the Universe had a cause.
Why are some people persuaded by this and others not?
First, 'whatever begins to exist has a cause' is very abstract. It references these concepts of existence, beginning and cause. How do you ensure you understand the same thing by 'cause', 'exist' and 'begin'? In an everyday situation, you have fairly easy ways of making sure you mean the word in the same way, but not in this context. In these contexts you relate the concepts directly to some things happening in the world, which removes ambiguity. Yet, could you even define a 'cause'?
Also, 'begin to exist' makes sense in my everyday context. But how the hell are we going to make sure we mean the same thing when talking about the beginnings of universes?
'a priori' confusion
Most of these Philosophical style arguments just leave you with confusion.
The concepts accessed are connected in complicated ways. Yet we would struggle to be entirely sure what the linkages and concepts even meant, let alone be sure that others understood them in the same way.
Thus, if a Philosopher wanted to write down a set of a priori truths in words, she would face the difficulty of not being sure what concepts to express and explain what she meant to others.
It also means there is too much work for the individual to do. Humans rely on the insights of millions of others to do things. Even me writing this relied on the mathematical and scientific innovations and implementations to make it possible for me to type and create words on a screen to send around the world. Thinking of suitable distinctions and definitions for deductions is hard, but for this type of reasoning it is upto each individual to work it out for themselves. Imagine if you had to do this in mathematics - you'd struggle to create addition, let alone set theory, differential geometry, group theory, number theory, decision and algorithm mathematics... Creating the right definitions is one of the most crucial part of mathematics and is hard. Likewise here we struggle to think of the right definitions to help us make deductions.
After all, the mass of experience in front of us is too much to then make deductions with!
If we cannot come up with agreed on starting points, we're kinda stuck. Yet the logic heavy Philosophers who have fewer problems here face their own problems. Certain issues - such as morality, existence, God... - are difficult (impossible?) to express in the notation of logic and mathematics. Perhaps these concepts will never be expressible in a format suitable for Philosophy?
More thinking lies ahead!
This article was written by 'The Sociable Solipsist'. He spends the time which should be spent on his degree thinking about Philosophy, and rumour has it that he's a great person.