Let's say you tell me to produce randomly a number from 1-100, and I choose the number 47. Can it be said that there is a specific reason I chose the number 47, and that it is not completely random? By random I mean that there is absolutely no reason this number in particular was chosen.

It seems odd to me, since it seems like since I have applied conscious effort to produce or choose a number within that range, or even without range, that it can't be truly random, but there might be a reason why I chose that number amongst the many others I could have chosen.

I guess the general question, which I'm interested to know if any philosophers in the past have discussed, is whether our thoughts are necessarily based on prior thoughts, or if thoughts can be truly spontaneous and random?

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    You need to define what exactly you mean by "random", as this changes how we answer the question. It seems you are getting at causal determinism. If causal determinism is true, nothing is intrinsically random in that it could not have come about without a cause. However, if you define random as merely unpredictable, then causal determinism is irrelevant and obviously a man could generate an essentially random number (in that it would have low predictability). – stoicfury Dec 23 '11 at 7:23
  • If thoughts were spontaneous and random, your behavior would be completely erratic and insane. There is no way, short of the ole' monkeys writing Shakespeare, you could have posed this question. – Devin Burke Dec 23 '11 at 9:21
  • @Justin: presumably if all our actions were random, yes, we would be ready for institutionalization. But the OP is just asking about a random number. – Mitch Dec 23 '11 at 19:53
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    Very complex subject: en.wikipedia.org/wiki/Entropy_(information_theory) – Sklivvz Jan 10 '12 at 21:16
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    Have a look at this question. – ThisIsNotAnId Mar 24 '12 at 0:17

15 Answers 15


Yes, many philosophers have discussed the question of free will vs determinism. Too many to mention here, in fact.

The notion of "randomness" (and the associated concepts of "choice" and "chance") are suprisingly difficult to pin down.

Jacques Derrida has a fascinating essay on the subject ("My Chances/Mes Chances"), but judging from the manner your question is posed, I imagine you are too unfamiliar with the underlying literature to glean much from it; I suggest instead you turn to some encyclopedias of philosophy to do some preliminary research on the subject.

  • Sure this is in the vein of free-will vs determinism but the OP has narrowed it down to a very very specific problem which might be assailable. – Mitch Dec 23 '11 at 19:56
  • I don't see how it is assailable without solving the whole free will/determinism debate first; if there is free will, one can spontaneously "choose" (in an unmotivated fashion) some number; if determinism prevails, one cannot. It seems to me that this specific case reduces to the general case without loss of generality. – Michael Dorfman Dec 24 '11 at 11:11
  • I'm just pursuing an argument.... I kinda agree with you. But I can imagine their might be a biological mechanism that'd be particularly specific to creating random numbers. Then there's still the separate idea that things may be deterministic but we can't ever know enough to practically distinguish high complexity from free will. – Mitch Dec 24 '11 at 14:31
  • Can we imagine a "biological mechanism" which would not be deterministic, and yet does not involve free will? From what source of entropy would the random numbers arise? In practical terms, of course, you are correct-- there is no way to distinguish deterministic, random and freely chosen numbers from each other, so the whole exercise is moot. – Michael Dorfman Dec 25 '11 at 10:25
  • I jeepnhearing that there is a physical mechanism, a Geiger counter recording the truly random decay rate of particles. So I could imagine a biological mechanism implementing something similar. – Mitch Dec 25 '11 at 13:29

Ok - let's say I tell you a number between 1 and 100 inclusively, which is random - how could you prove it?

Of course, if I say 1, 100, 99, 42 or 13, most people will claim it wasn't random, because their first thoughts where about the same numbers, but if these numbers where excluded, then it wouldn't be a fair draw from 100 numbers, but from 95.

So from a single number, you can't distinguish a biased number from a random number. I can tell you a number, and you can't prove it isn't random, but you can't prove it is as well.

So I could tell you my technique, how to generate the number, and convince you. If most people could learn the technique, and you coulnd't tell before, what number the people are producing, and more: if the repeated usage of the technique would lead to an uniformly distribution over the numbers from 1 to 100, we would call this a 'Yes, we can'.

Ok. So I take a sheet of paper, write the numbers 1 to 100 on small pieces of it, put them in a bag, and pull a number - mission accomplished! :)

That is cheating!

Is it? Ok - we then need to see how to sharpen the rules, I guess? No tools allowed, like paper and bag, RNG and dices?

Ok - I pull a lot of hairs out of my head - much more than 100, let's say 500 to 1000 hairs, and then I count them, and take the modulo. :)

That is cheating!

Is it really? Well, of course the technique doesn't scale. It can't be repeated very often; not often enough to check, whether an equal distribution is reached. And you could tell, that the rules prohibit any material as tool.

Ok. Then I'm nearly to the end of my wisdom. For a random result, I need some unpredictable input, and of course, my brain isn't a good source for such an input. I could name a measurement, which would work for a small amount of small random numbers (1-10), and it works similar to the hair example:

I think about a song I know, and the first song which comes to my mind, I count the characters. I can't predict from the first song - "I am the walrus" how many characters it has. The number is pretty big, compared to the number range (1-10), and I take the modulo, and have a random result.

So this is a proof of concept, and the next time, I would, of course, have to choose a different song, and so the number of experiments is limited to the number of songs or poems I know, and it is a time consuming procedure.

If the rules say 'name a number spontaneusly - in 2 seconds', I'm pretty sure nobody can produce repeatedly random numbers. But given enough time, you can.

  • I quite like this response and the modulo was exactly what I was thinking: pick a huge number (random as you can), and mod it to be in the correct range (mod 100 + 1). – mfloren Oct 26 '16 at 17:38
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    Computers commonly use the current time as their random seed. Humans could do likewise: use your best estimate of the current time to the second, modulo an odd number (to ensure that the part of the time that you're bad at estimating gets lost in the shuffle). – Brilliand May 31 '17 at 21:56

Empirically, humans can't choose truly random numbers.

If our thoughts aren't based on our prior thoughts, what are they based on? If you don't have something to build off of it seems like you don't have anything.

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    By your argument, a newborn must either be "born" with thoughts or not be able to have any thoughts of his/her own, ever. Stimulus from the environment forms basis for "new" thought, yes? – ThisIsNotAnId Mar 24 '12 at 18:54
  • @ThisIsNotAnId I can use the environment around me to generate a random number. For example, on my computer I always display the number of seconds so that I have a psuedo-random number generator to use when I want one. However, that is not me generating a random number. Taking in input from the environment is not generating. – Keller Scholl Mar 28 '12 at 21:05
  • @KellerScholl Aren't you falling in plain determinism? Not that I have a problem with it, but in that approach, there's no random at all. – Alpha Apr 14 '12 at 1:58
  • Your link is broken. – njspeer Apr 11 '18 at 0:52

I think that this question has been answered to some degree outside of philosophy. There are several mathematical studies that have demonstrated that when humans are asked to provide strings of random numbers, they turn out not to be random at all, and that similar patterns may be found within the strings. The philisphical question is of course, are the patterns real? There is an occurrence of the same integer, and adjacent integers, and integers within specific sets of 10 from one ending in zero to the next,(10-20, 20-30,etc.) that greatly exceeds statistical probability of the occurrence. If given a choice from 1 to very large numbers, say a trillion, the strings are skewed toward lower numbers.

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    Any chance I might be able to persuade you to back your answer up with references to some of the studies you are talking about? – Joseph Weissman Jan 7 '12 at 18:06

Yes, of course. People are capable of generating random numbers.

Even if we could ever precisely pin out the reason why we choose a particular single number, that's not to say it wasn't random. There might be a very good explanation showing it is intrinsically unpredictable. And while we can't pin that, it is unreasonable to argue if our choices are deterministic or not.

With that, to me it's pretty clear anyone can think of a completely unpredictable number for any practical purpose. But let's leave the discussion about randomness and free-will aside. Even though this may turn the question into non-philosophical...

Despite what's shown in the movies, some amnesia cases turn people unable to remember anything, while maintaining the brain working seamlessly fine, having new thoughts normally, unrelated to previous thoughts. Those thoughts couldn't be related if one of them just don't exist anymore. They are forgotten.

So the philosophy here gets another focus: if you agree that thoughts are generated by the brain. Then most likely there's no correlation between generating new thoughts and previous thoughts.

Now, that's not to say we always generate random numbers when we try. That's a whole 'nother question.


Douglas Hofstadter has something to say about randomness in his book Godel, Escher, Bach. In chapter 19 he explores the complexities of mathematics and meaning as they could apply to Artificial Machine Intelligence. Its a daunting subject, and Hofstadter chooses to understand human intelligence as having the 'right stuff' to randomize. I should add he does not detail a specific human capacity for randomization. He recaps his thoughts on creativity itself within the general frame where machine and human processes, might, possibly intersect.

"It is common notion that randomness is an indispensable ingredient of creative acts. [...] This world is a giant heap of randomness; when you mirror some of it inside your head, your head's interior absorbs a little of that randomness. The triggering patterns of symbols, therefore, can lead you down the most random-seeming paths, simply because they came from your interactions with a crazy, random world. So it can be with a computer program, too. Randomness is an intrinsic feature of thought, not something which has to be 'artificially inseminated' whether through dice, decaying nuclei, random number tables, or what-have-you. It is an insult to human creativity to imply that it relies on such arbitrary sources." (p.673)


See, I believe that there is quite a confusion between 'randomness' and 'unpredictability'. Unpredictability is when WE can't pin down the outcome. We humans don't know everything so we aren't able to pin out the reason for the generation of that particular number, and the number, but, it(the reason) still exists.

Let's assume that there is a consciousness called 'Reality'. It knows everything and can analyze everything. This Reality has a brain. So, this Reality can pre-calculate every human action, or the string of random number(s) based on their experiences in this case. One can't permanently delete his experiences. Even if he/she is an amnesiac, they remain in the subconscious part of our brain, and based on his/her experiences we do everything. Also, forgotten means irretrievable. It's there, but you can't recollect it. It doesn't mean permanently erased.

Random is something that our friend Reality cannot pre-calculate. It has no roots, no origins, no subconscious reasons. It just is there. Nothing can generate random numbers. There always has to be something, or some reason to everything. Even computer random generation algorithms have a seed, i.e., the number starting from which the random generation algorithm is executed.

So, humans are incapable of producing a random number. We can make a unpredictable number, because our algorithms are unique and highly complex, but not a random one.

Source(s): Intellectual combat


I don't believe a single person could generate a truly random number, but two people can (with the same premise that a person will randomly win, draw, or lose when playing Rock, Paper, Scissors).

  1. Between you and your friend, establish who will be "initial", who will be "final" (must pick different ones); e.g. Adam is initial, Bill is final.

  2. Establish the integer range; e.g. -5 to 18.

  3. After a synchronized count down, both people simultaneously call out a number within the range; e.g. Adam: "-2", Bill: "9".

  4. Take the positive difference of the two numbers; e.g. |-2 - 9| = 11.

  5. If initial <= final, then add the difference to the minimum; e.g. -5 + 11 = 6 (6 is your randomly generated number).

  6. If initial > final, then take the positive difference, subtract it from the maximum, then add 1; e.g. initial = 15, final = 8, |15 - 8| = 7, 18 - 7 = 11, 11 + 1 = 12 (12 is your randomly generated number).

Step 6 makes sense if you imagine that you may only count up, and that the number immediately after the maximum is the minimum; e.g. 16, 17, 18, -5, -4, -3 (that is where the extra 1 comes from).

Flaws: Just like in Rock, Paper, Scissors, players don't pick all choices with equal tendency; people use this knowledge to their advantage by anticipating what the other person may pick; e.g. Adam tends to pick odd numbers more often than even numbers, Bill knows this and wants an even number, therefore Bill would pick a low odd number, or a high even number.

  • Very interesting. This might get more random the more participants there are. But even then, if you had a hundred participants, the resulting number would be random from each individual perspective, but as a whole, I wonder if there is non-randomness in the result, whatever that means. – Snowman May 4 '15 at 15:00

Thanks for this great question :)

I think something else should be defined also. It may be possible for some minds to produce such number without any effort on the conscious side. But I think that our sub-cons will effect the number produced.

Also, our sub-cons is effected by everything environmental + our own cons., therefore "us", producing a "fully random" number is impossible.

A simple example, let's ask 100 people to give us a random number, and we simply do not give any ranges. I think most of the people will give us "small" numbers, like between 1-1000, because we use little numbers in our daily life most of the time :)

We sometimes forget that our cons. is also effected by our sub-cons. and it is very hard to be objective at all times.


I'm reposting this, almost verbatim, from here:

To answer your question, or at least get at some sort of picture, let's consider the following. What is random? Hmmm. Without getting into the details of the matter, or philosophical implications, we may define "random" in a very intuitive manner as this will mostly do for a discussion of this scope. Let us then propose that an event which is "completely" random is one for which it is logically (or formally, i.e. in the sense of mathematical rigor) impossible to associate any rule, pattern, or reason1. This is, of course, where it all gets tricky.

In the way "random" has now been defined, it may be possible to generate an event, at least cognitively, which would be viewable as truly random. To take your example a bit furhter, let us conduct a thought experiment. Imagine we're walking down a busy city street. We decide to ask every person that passes by, and decides to stop and give us five seconds of their time, to pick a number. By this, we may construct two sets. Let set X denote the numbers we record, in the order we encountered them; and let Y denote the set of indicies of the people who stopped and gave us a number. So, for example, if the third, seventh, and twelfth person we asked stopped and gave us a number, Y = {3, 7, 12}. Certainly, the sets X and Y may not be random in the sense that we have defined.

But, then we may ask the question why the sets have the particular pattern or rule associated with it. Could there not have been different sets? And so, by our criterion for true randomness, the reason the sets X and Y are what they are, is random. I can't come up with the proof for the criterion off-hand, but I suspect Goedl's theorem's in there somewhere.

It is worth noting that by our definition, it may be the case that no event which occurs in nature could be viewed as random. So, that may answer your question about people being able to generate random numbers. On the other hand, we may very easily have events that qualify as truly random as long as they exist in some "virtual" reality as the one discussed in the example above. But, it's truly an understatement when I say that that's a topic best left to be discussed another time.

1 At this point the concept of reason becomes very important. It would do us well to consider exactly what may be viewed as reason, the concept of of cause and effect, etc. However, for the discussion, we shall rely on a mostly intuitive notion of reason, and leave the detailed discussion of the matter to more able hands.


We cannot choose random numbers. Our actions are a result of other actions, which are a result of other actions. The trouble is that the whole system (our world) is so complex that it is impossible, in practice, to predict its behavior accurately enough and, thus, free will seems to exist (the striking thing is that actions we take now were conceived 4 seconds earlier). For further examples, you may want to refer to the works by Sam Harris (or even Marvin Minsky and many others).


I appreciate the well thought out answers, but I think this topic could benefit from some objective statistical analysis, e.g. one subjects responses to several random number queries plotted over time, a large group's individual responses ranked by volume of occurrence of each number in the range, etc.. Would we see that most answers are bunched up in the middle or in the upper half of the range? Would we see that very few people pick numbers at the extreme top and bottom of the range? In essence, can we make "random" human response more predictable, and what do the observed patterns say about human nature?

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    This is an interesting point, but only shows whether humans can be pseudorandom number generators. I had a professor once who asked everyone in the class for two random integers. He then told us about a theorem in which (two random integers are coprime with probability 6/pi^2)[en.wikipedia.org/wiki/Coprime_integers#Probabilities]. Sure enough,the numbers that we had "generated" were a pretty close approximation. So, that would seem to satisfy your point, but it doesn't address whether some deterministic but seemingly-random process generated those numbers in the first place. – James Kingsbery Oct 15 '14 at 18:52
  • there are such studies concerning passwords; the entropy of human generated passwords is about 2 bits per character (instead of 6 bits) - see en.wikipedia.org/wiki/… – nir Oct 16 '14 at 21:39

I've been thinking about this problem as well. Human randomness has been shown to be exploted. For example, the TV show Brain Games has exploting what you think is "random" many times. They use ques, science, math, or somthing along thses lines, to know what you'll choose ( along with everyone else ) before you even choose it. This idea is frankly scary. With the rise of computer learning, what if computers get better at predicting your moves. If I, a hacker, wanted your information, I could create a nerual network, so slowly learn what "random" outputs you produce, by watching online content, seeing what you type and do, seeing how you think, and adventually being able to predict what you consider "random" to the point where I could use this software to guess your pins, and maybe even passwords.



Yes. In fact, there are always reasons for everything. You might be the reason.

I will choose the words random and arbitrary as pertinent to your question. There exists a subtle but important distinction between the two. According to Google word origin, the word arbitrary means


While random means

Middle English (in the sense ‘impetuous headlong rush’): from Old French randon ‘great speed,’ from randir ‘gallop’

(Emphasis added).

What we perceive as randomness is nothing more or less than either a deterministic or arbitrary action (or a combination of the two) that occurs too rapidly for us to trace its true causes. (Pseudo-random number generators operate on this principle. Given an exponential but finite amount of time, a human being could always reverse engineer the compact logic generating a pseudo-random sequence.) Other answers here also have given reference to a chaos factor, or the speed at which supposedly random samples are produced or judged plausibly as "random". All things have causes, and therefore randomness in the sense of having no cause (which I assume is synonymous with your usage here of the word reason) does not exist.

Our choices can be built on a mix of prior experience, reason, and our own volition, potentially making them seem random to someone who is not acquainted with our experiences, our reasons, or our tendencies of choice. The element of choice is what makes it possible for our actions defy external explanation entirely, which is often conflated with being "random" in the sense of being causeless. However, the lack of a finite or brief communicable reason does not imply causelessness: the cause, rather than being a set of purely deterministic laws, is one's own volition.

Given this model, there is no such provable thing as true randomness (causeless and unexplainable action or variation).


Random is by definition the lack of predictability. So if it is possible to predict an event, it cannot be random.

The inverse question would then be: Are there some things that man cannot predict? Answering that question would indirectly answer your question as well.

So is a dice roll random? Well, lets see:

Lets assume that you have the equipment to measure the exact starting conditions. Assume also that you have a supercomputer that can simulate the dice bouncing around on the table. Would the dice roll be random? It would seem, no, because the dice result can be calculated from its starting conditions.

But lets question the assumption. Due to Heisenbergs uncertainty principle, it is impossible to measure the exact starting conditions (the starting conditions are affected by the very act of measuring them. The more accurate you try to measure, the greater you affect the very accuracy you are trying to achieve). And if the system you're going to simulate is chaotic (versus linear) http://en.wikipedia.org/wiki/Chaos_theory, then any error in measuring will cause deviations in the simulation that grows exponentially in magnitude, causing very different results. Since even the most accurate measurement technology wouldn't be able to account for this exponential deviation growth and inability to measure extreme accuracy, you could say that it actually is possible to generate randomness.

But lets question that result even more. The randomness is based on the fact that there is a limit to how far into the future we can predict about a given chaotic system (the limit depending on how chaotic the system is). So that means that if we only try to predict within the timelimit, we can actually make moderate predictions about the result. Once we move beyond the limit, our predictions will be so off course that they become unusable.

Ok, so where are we now? In order to generate an unpredictable event, we need a system with the following properties:

  1. The system has to be chaotic.
  2. The system has to be very sensitive. That is, it must have a very early "prediction threshold" beyond which it quickly degrades into very chaotic and unpredictable behaviour (otherwise we would have to wait too long before the results could be considered random).

Radioactive decay is such a system (the stuff we measure in a Geiger Counter). We are simply unable to make predictions about when radioactive particles decay because its impossible to detect the starting conditions and accurately simulate the system (due to Quantum theory, Heisenberg Uncertainty principle etc). All we can see is that it happens with no visible pattern. http://en.wikipedia.org/wiki/Brownian_motion is also such a system.

In theory, if we had a magic instrument that could measure the starting conditions and then simulate the radioactive decay with 100% accuracy, it would only be as predictable as an random-number-generating algorithm for which you already knew the seed (the seed is a number that is essentially the starting condition for the algorithm).

But who knows. Maybe such a magic device exists, and we have yet to find it.

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