What is true?

There are three ways we might say that something is true:

  1. It is self-evident?

  2. It accords with the facts?

  3. It is consistent with our knowledge and reasoning?


To know something is the case without reasoning or using sense experience is to use intuition. For example, in 'a straight line is the shortest line that can be drawn connecting two points,' we do not imagine every possible scenario, let alone observe every case, nor do we use reason. It is something we intuitively know as true. (Even if it isn't true in all mathematical systems!) Likewise, if we recognise something as great art, then we may not be able to categorise every reason that makes it great art. Similarly, in English, no one can state the rules for the use of the word 'the' in every case, but native speakers intuitively know what is right.

However, have you ever refused to do something because you were afraid? Have you ever felt that something could be so good for you that you jumped in without thinking? Aren't some things which are so obvious at the time, later considered rash and misguided? Does this mean that intuition depends on such things as:

  • Being free of early trauma?

  • Being unselfish?

  • Being free of cultural conditioning?

  • Being unemotional?

  • Using reason to dispel the irrational?

Strictly, intuition is a clear, certain and immediate knowledge that something is so. Some types of intuition, such as knowing that a given artifact is a valuable antique may require that we know about antiques. So other types of knowledge are important. The list of conditions above for true intuition are a rough jotting down of ideas, rather than a comprehensive list. Reason is mentioned in the sense that for an intuition to be true it might have to agree with other knowledge. This does not mean that the intuition was arrived at by reasoning (which is contradictory), simply that reason might be needed to support it or to eliminate barriers to intuition.

According with fact

Suppose we all landed on Mars, a dusty dead planet. I see a bunch of grapes growing on a vine. I look away, and look back and they are still there. I eat one, and carry out various tests, all proving that there is a bunch of grapes growing on a vine. I call you over, and you to can see and experience the grapes. (Or you say you can't see them, and that's the end of it, I'm hallucinating!) We involve others and they all see the grapes and have the same experiences (by now they've probably eaten most of them, though.) Do we conclude that there is a vine with grapes growing on Mars, a dead planet with no water, or what? The evidence accords with the facts, so I suppose we do.

Is consistent with our knowledge.

So back to Earth we go. 'How was Mars,' they say and we tell them about the grapes. What is their reaction? Pull the other one! 'Vines grow on soil with water. You didn't see any grapes or a vine.'

And are they right?

Yes. These observations are so inconsistent with our whole body of knowledge that they just aren't acceptable. No water, no grapes!

Suppose we say, 'Well, go and look for yourselves!', and off they go and low and behold they see the grapes. In this case, they have to change their theories. However, on most occasions this will not occur. We may well have thought we saw grapes, but what we really saw was different. Some Alien playing a trick? Hypnotism? Space hallucinations? But not grapes!

Does this sound like some group of arrogant scientists opposing challenging theories and experimental results? Does this show a lack of open-mindedness? Does it mean that consistency with other knowledge is not a guarantee of truth?

It appears that consistency with other knowledge is an essential of something being true, if we take knowledge to mean that it is true. However, what we claim as knowledge now, might not be what we claim in a 100 years time. Therefore what we now think is knowledge might be false.

In the Mars example, if the evidence we gave about the grapes were reliable, then further investigation would be required. If the grapes were videoed, and otherwise tested and we brought a sample back then our story would be all the more believable. But consider other examples.

A certain Eastern guru can make diamonds appear out of thin air. Is this believable? Of course not. It does not accord with what we know about science. Also, if such a person could do this wouldn't they be rich? Feed the starving? Help the suffering and the sick? If they, as holy people are above this sort of thing, how come they are not above showing off in front of their disciples? Sounds more like a charlatan than a shaman, doesn't it?

We might conclude from this that we can trust our judgements on the truth of sense experiences, intuitions, and evaluation of information if we do this while in the right conditions and if our observations accord with fact and knowledge.

None of the above guarantee truth. We need to use all of them to


  1. (Of an intuition) Is this self evidently true? Am I being influenced by strong emotion or desire? Am I being influenced by my past experience? Early experience?

  2. (Of fact or information) Does it accord with fact, experiment, experience? Am I observing under the right circumstances and conditions?

  3. (General) Does it agree with what I already know about the subject? Does it agree with common sense?


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Next: What is impossible.


Last modified on: 27-Sep-98.
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