Consider the following argument:

If want to know that something is true, I need to first know what is truth. If I need to know what is true, I need to find the truth. (Is there any other way to know about truth?) BUT If I want to find something, I need to know that thing. and to know something I need to find it.

Corollary: Truth is impossible to find.

I am a newbie to logical thinking though I am a programmer.

It's the kind of reasoning which came up to my mind. How could I more precisely reason about this problem?

UPDATE 9/8/2017

From Politis Philosophy GuideBook to Aristotle and the Metaphysics I found this passage / Answer

"To search for an explanation is to search for the answer to a ‘Why?’ question (dia tí; ‘Why?’). But we can only ask ‘Why?’ questions if there is something that we already know or something that at least is already evident to us. This means, Aristotle argues, that we can search for explanations only if, to begin with, there is something that we know, or that is evident to us, directly and without this knowledge involving a search for explanations. And he argues that such direct and non explanatory knowledge is, precisely, sense perception."

  • Theoretically, yes. Sep 2, 2017 at 21:59
  • Related: philosophy.stackexchange.com/questions/8216/…
    – Philip Klöcking
    Nov 15, 2017 at 16:16
  • Finding truths is definitely possible, finding important truths harder; finding all important truths is much, much harder, and maybe impossible except for the truly enlightened - and these people are rare. Nov 16, 2017 at 2:05
  • I find this argument unconvincing, partly because it is possible to find truth (or even Truth) when one isn't even looking for it. .
    – user20253
    Nov 26, 2017 at 9:52
  • The situation is paradoxical. Think about leaves: All leaves are similar but yet none of them are same or at least no one is sure about. One can carelessly say that: Finding leaf from non leaf is possible. But One can't define a leaf in its purest form. Nov 27, 2017 at 8:13

9 Answers 9


You've stumbled upon an old problem in philosophy, The Paradox of Inquiry, first formulated in Plato's Meno.

The problem can be reformulated as follows:

Either you know the answer to a question, or you don't. If you do, then there is no point searching for it. If you don't, then you will not know what to search for.

The short answer is that you can still recognize a correct answer, even if you don't know what you're looking for beforehand. (Simple example: you don't know what the prime factors of a given number are. You try some combinations and eventually you recognize the correct answer simply by multiplication.)

A more recent version of the problem is Moore's Paradox of Analysis.

  • There is also the issue that for many philosophers the task is one of remembering, not creating. If Truth is always known by identity and can only be known this way, as epistemologists commonly conclude, then we already know it but have forgotten, in which case your problem does not arise, or not in the same way. The OP's corollary is false in my opinion and needs to be proved before building theories on it. .
    – user20253
    Nov 27, 2017 at 12:41

shouldn't it be:

If I want to know that something is true,
I need to first know what truth is.
If I need to know what truth is,
I need to find out how something is true.

It does not follow that:

If I need to know what is true,
I need to find the truth.

In short, "truth" is a noun, "true" an adjective. Truth is merely a condition of propositions. This condition is satisfied when what is said is corresponds to (matches, fits...) what is (the world, the case, states of affairs...) "True" is an adjective used to describe sentences (propositions, statements...) which satisfy the truth condition. "False" (or "nil") is an adjective used to describe sentences which do not satisfy the truth condition. For example, "Obama is President" is a true statement. This time next week, that same statement will be false.

If I want to find something,
I need to know that thing.
and to know something I need to find it.

It may be sufficient that you know a thing and are able to find it, but it is not necessary to know that thing to find something (whether or not something is that thing).

Knowledge is empirical verification of what is - else how do you know what is? If you want to stretch "find" to mean "empirically verify" you are, of course, free to do so.

Is truth something you "find" or is it the result of evaluating an expression (read: rationally assessing a truth value)? You might enjoy chapter 9 in this book.


It's a good question. But your conclusion, that truth is impossible to find, is not correct. Have a look at the idea of 'knowledge by identity'. This is not a matter of logic or reason and does not suffer from the uncertainty to which the conclusions of reason and logic are prone.

'Truth' can only be what we know to be true. Thus 'true knowledge' is the issue here. For Aristotle, who was well aware of the limits of analysis, the only true and certain knowledge is an identity of knower and known, where the knower is one with the object of knowledge. This is the only certain knowledge we can have, thus the only form of truth.

In this way the Oracles' advice to 'know thyself' is relevant. We see this in Descartes initial axiom, for he realised that only our identity is certain knowledge.

What can we learn from our own identity? The mystics would say that all metaphysical truths can be known from this. Lao Tsu, among many others, claims to have learned how the world begins and ends in this way.

We may not believe him, but at least he does not claim to know truths in any other way than logic concludes they can be known. Don't give up on truth. It is there to be discovered if we use the correct methods to search for it. But it is not truth until you know it is, so you won't find it in a book.

You do know at least one metaphysical truth, which is 'I am'.


Before you can find "truth," you need to define (or agree to someone else's definition) what "truth" is/means. Then, using that definition, you compare the various statements to determine if they meet the definition. If they do, then you found truth, otherwise, you did not.
Since all it takes is one true statement to find truth, then it is very possible to find truth. For example, 2 + 2 = 4 or, 2H + O -> water molecule or, the sun rises and sets every day, etc..


To know that something is true means to know that something is the case. For example if one makes the statement p, ‘The sun rises in the east’, and you want to find out if p is true, you need to go out there and observe the rising or not rising of the sun in the east. If the sun rises in the east, as has been the case for us humans for thousands of years, then we say that p is true. This is called inductive reasoning, which has served us very well and allowed us to make magnificent technological progress. You don’t need to know what ‘truth’ is. Truth is just another way of saying that something is the case for a particular object or event in a specific time and place. In other words, Truth is not a Platonic idea to which all things partake in order to obtain the property of trueness. This means that truth is not absolute but relative to the perspective we take. Outside our specific perspective the notion of truth does not make any sense. For example, if you live on a space station and make the statement p, ‘The sun rises in the east”, then p is meaningless. In space there are no cardinal points, or up, down, left, right. All these orientations make sense and can have a true/false value only if we decide to adopt a point of reference, to which these orientations will be relative. In addition, we assume that the laws of nature are true everywhere in the universe. We make assumptions in order to work on our theories to build models that would explain the world. And know very well that progress is made only when our models are falsified. In which case we are forced to change our assumptions (what we held as true) about the world and proceed to build new models on the basis of the newly acquired knowledge. To know that p means that we take p to be true, until evidence proves otherwise. This is how knowledge progresses, by revising our beliefs or what we hold as true for a particular object or event.


No, you don’t need to know what truth is before you decide that something is true or not. The way we use the concept of truth is with a predicate, i.e. truth is with reference to the subject of a proposition, and all we need is the verification of our senses. For example, if you want to know that a certain cat (e.g. Schrödinger’s cat) sealed in a box is dead or alive, all you have to do is open the box. If you do open the box and find that the cat is dead, then your earlier statement (if you made one), p = The cat is dead, is true, else, according to Quantum Physics, the cat is both dead and alive at the same time (in Nagarjuna’s tetralemma: p AND ~p is the case just before you open the box, which does away with Aristotle’s principle of non-contradiction (law of the excluded middle, i.e. either a proposition is true or its negation is true.)

In Mathematics we have no need for the verification of our sense, but we must follow a series of steps (rules, laws, procedures) determined by logic and, sometimes, by intuition.

Platonists on the other hand believe that there is such a thing as Truth, an Ideal Form, which has little to do with the truths revealed by our senses but is like the truth revealed by mathematics. The same applies also to other concepts, e.g. Justice, Freedom, Good, Evil, etc. But this idea has no practical value in a mundane world.

Nietzsche said that all such terms (those above) are governed by conventions and we must not forget that they are metaphors, metonymies, etc.: “What, then, is truth? A mobile army of metaphors, metonyms, and anthropomorphisms—in short, a sum of human relations which have been enhanced, transposed, and embellished poetically and rhetorically, and which after long use seem firm, canonical, and obligatory to a people: truths are illusions about which one has forgotten that this is what they are; metaphors which are worn out and without sensuous power; coins which have lost their pictures and now matter only as metal, no longer as coins.” (Nietzsche: On Truth and Lie in an Extra-Moral Sense). For Nietzsche, and for a lot of other people, “Truth … the ‘thing in itself’ (for that is what pure truth, without consequences, would be) is quite incomprehensible to the creators of language and not at all worth aiming for.” (Nietzsche: On Truth and ...etc.)


Depends, my way of finding a truth is first put yourself in their reasoning, then find flaws, it takes only one flaw to make the whole thing untrue. But if you consider that when you put yourself in their shoe you are already biased then what can I say?


You can find truth in a system of rules. If all rules are met and there is no logical contradiction, then it is true in that system. People believe in these systems and find the truth in them, which does not necessarily apply to contexts outside of these systems where some of the rules are not met. The more rules you reject, the harder it gets to find the truth, because there can be more and more explanations for the same phenomenon. What you can do is somehow merge them, so all or most of them can be true and accept this logical structure as truth. If you do it properly, then you end up with a relative simple universal theory which explains everything around you including religions, science and everything else. This is called enlightment. This is the structure which matches reality. It is achievable, because I already did it in meditation. Reaching it consciously and describing it with mathematical formulas is a lot harder.


I totally agree that you have to define truth before you can set out to find it. Personally, I value practical truth over anything else.

The way I define practical truth is basically any position that would grant me predictive capabilities. For example, by holding the position that dieting helps lose weight, I would be able to accurately predict that I will lose weight if I take in fewer calories. The position is true by means of confirming the predictions.

This definition of truth is attainable because it's testable. You can't really consider a position true until it has been tested though, so you first have to formulate some positions and test them out.

What is truth?

  • 1
    I'd suggest that a truth is something we know to be true. What else could it be? Being able to predict on the basis of a theory does not prove the theory true, just plausible.
    – user20253
    Sep 6, 2017 at 12:10
  • I think I agree with that. I think "plausible" is what I mean by "practical truth". Sep 7, 2017 at 19:16
  • It is emphasizing the importance of scientific truth. There are truths which are valuable even they can not be tested but one can only argue about them. e.g existence of God if you are believer and vice versa. Nov 27, 2017 at 8:22

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