Plato and Aristotle on Weakness of the Will and the Paradox of Never Knowingly Doing Wrong

            The assertion thatno-one ever does wrong knowingly (and several variations thereof) is attributed to the historical and literary figure of Socrates in several of his pupil Plato’s texts. The paradox is not self-referentially obvious, as it is in Socrates’ declaration, “…I still know nothing…” (Republic 354b), where Socrates clearly has to know at least one thing, that he knows nothing, for the statement to be meaningful, albeit false. The paradox here is much subtler and lies within the consequences issuing from that statement. It establishes a causal link between knowledge and moral action – in knowing what the right thing to do is, one cannot choose to do otherwise – that is not immediately obvious without further investigation. So too, inherent within it, are metaphysical implications with respect to the nature of moral knowledge itself – what it is and how we come to know it – and the wider implications it may have for what we perceive to be our own free will and agency. Plato tests this moral theory, with Socrates as the protagonist, across a number of different dialogues but, for the purposes of this essay, I will refer exclusively, from this point onwards, to the Protagoras.

            The philosophical problem of weakness of the will, in the broadest sense, refers to the seemingly all too human phenomenon of ostensibly understanding intellectually what the right course of action would be with respect to one’s moral obligation to oneself and yet, in full conscience, succumbing to a morally inferior, alternative course of action due to an influence or influences that have less to do with one’s moral reasoning and more to do with apparently overwhelming emotional impulses such as desire, anger or fear. Weakness of the will is not synonymous with amorality or with what St. Augustine called immoral rebellion or sinfulness. It has nothing to do with purposefully or calculatedly doing something which one knows or believes to be morally wrong with respect to another person or any other sentient being. Weakness of the will is exemplified by that familiar and peculiar trait of human fallibility in which one presently yields against one’s own better judgement to the detriment of one’s own long term happiness and wellbeing.

            For Socrates, any failure that might be attributed to a so-called weakness of the will lies in the assessment and description of the phenomenon itself. This is made clear when he says to Protagoras,

            The opinion of the many concerning knowledge is something like this, that it isn’t a strong thing characterized by either leadership or rule. They don’t think about it as though it were any such thing at all, but often when knowledge is present in a human being, they think that it is not the knowledge that rules him but something else – now spirited anger, now pleasure, now pain, sometimes erotic love, many times fear. They simply think about knowledge as they do about a slave, that it is dragged around by all else.


He wishes to refute the opinion of the many:

            …knowledge is both noble and capable of ruling a human being, and that if in fact someone knows the good things and the bad, he won’t be overpowered by anything so as to do anything other than what knowledge bids him to do…


The crux of his argument is:

            …for this alone constitutes bad action, namely being deprived of knowledge…


            It is clear that, for Socrates, knowledge can never be slave to the passions, and weakness of the will, therefore, is a misnomer which more accurately amounts to a deficiency of the intellect. An individual acting erroneously, against their own best interest, does so simply because they know no better. Even when a person truly believes that they do in fact know what the good and right thing to do is but, for whatever reason, feels compelled to act contrary to it, the problem, according to Socrates, remains one of cognition in that they are actually mistaken in that belief.

            In his Nicomachean Ethics, Aristotle responds specifically and bluntly to this point when he says,

            …no one, he [Socrates] would say, acts contrary to what is best while grasping that he is doing so, but only because of ignorance. Now to say this is to say something at odds with what patently appears to be the case…


            Aristotle’s starting point is to acknowledge that there appears to be an overwhelming body of empirical evidence in support of the existence of a certain kind of disposition of character which is inclined towards weakness of the will, or lack of self-control, or what he calls akrasia. He then attempts to argue that akrasia can and does occur, not, as Socrates maintains, as a negative function of lack of knowledge, but in response to some other impulse, despite the individual in question truly being in possession of all relevant moral knowledge. The distinction is very important in terms of what follows from it; it makes people culpable for their behaviour and determines how we might reasonably judge and respond to that behaviour. It has practical implications in terms of forgiveness, reproach and punishment. If it were true that no one ever knowingly did wrong then it would necessarily follow that one who does wrong does it unknowingly. In which case, where would we lay blame?

            Aristotle does not argue from or for the position of “the many” as Socrates describes and rebukes it. Rather, his intricate investigation into the possibility of weakness of the will begins with the assumption that the human soul is divisible into parts,

            …one aspect of soul is non-rational, while another possesses reason.


            He first describes the rational element of the soul, it being comprised of two different kinds of knowledge: sophia, which relates to logic and intellectual accomplishment in theoretical abstractions, and phronēsis, or prudential reasoning, which relates to deliberative, practical wisdom, both of which he regards as excellences,

            …one by virtue of which we reflect upon the sorts of things whose principles cannot be otherwise, one by virtue of which we reflect upon things that can be otherwise…


            Sophia is characterised by precision and refinement and its objects are pure mathematics, philosophy and eternal, objective moral truth. Antithetically, the objects of phronēsis are contingent things and phronēsis issues itself in judgement and decision making. In addition, Aristotle argues that character disposition, which is an element of the non-rational or ‘listening’ part of the soul, is also essential to all evaluative judgements leading to moral action:

            It remains therefore for it to be a true disposition accompanied by rational prescription, relating to action in the sphere of what is good and bad for human beings.


            Phronēsis then, though itself rational, is inextricably linked to our non-rationality, aspects of which, with due care and attention, may also become excellent if one works purposefully and assiduously to overcome the appetitive, desirous and potentially recalcitrant elements of the soul which reside there. He observes that

            … excellence of character results from habituation…


I shall return to Aristotle’s ideas regarding “habituation” later.

            In Protagoras, Socrates does not describe anything which we might call soul or mind. He does not explicitly distinguish sophia from phronēsis or allude to any differentiation between the two1. Neither does his argument require any dissection of character disposition. Indeed, he contends that what outwardly appears to be akratic incontinence is actually an arithmetic failure in “the art of measuring” (P356d3) due to the deceptive “power of appearances” (P356d4):

            And what if the saving of our life depended on our choosing odd and even, when we had to choose correctly the greater and the lesser, taking either each in relation to itself or the one in relation to the other, whether up close or at a distance? What would save our life? Would it not be knowledge? And would this not be a certain art of measuring, since in fact the art pertains to excess and deficiency? And since this concerns odd and even, what else would this be other than arithmetic?


            The suggestion is that it is something akin to our mathematical understanding of perspective that allows us to correctly calculate which action we should follow through in any given set of circumstances. Precise perspective allows us to accurately compare the immediate outcomes with any anticipated future consequences of all present actions vis-à-vis. Assuming that future consequences can even be predicted with such accuracy, there still exists no room in this equation for anything we might call instinct, impetuosity or any other appetitive or emotional driving force for action. Choosing correctly amounts to having no choice at all.

            This is much too rigid a formula for Aristotle owing to the fact that human decisions are based on contingent factors, the potential outcomes of which are not always clear or calculable. Furthermore, he states that,

            …what is in the sphere of action can be otherwise…


For Aristotle, it is the interconnectedness of and interplay between the two different aspects of the soul that allow for the possibility of weakness of the will,

            Now the origin of action – in terms of the source of the movement, not its end – is decision, while that of decision is desire and rational reference to an end. Hence intelligence and thought, on the one hand, and character-disposition on the other are necessary for decision; for doing well and its contrary, in the context of action, are conditional on thought and character. Thought by itself sets nothing in motion; thought that sets in motion is for the sake of something and practical.


            He describes three desirable dispositions of character, each of which has a positive effect for the good in relation to decision making and subsequent action. Each, however, has an opposite and undesirable state. Of the three desirable states, enkrateia, or self-control, stands alone as the trait which can be fostered and grown with due attention and diligence2. Failure in this respect will contrarily dispose one to be akratic, or un-self-controlled, or weak of will.

            Aristotle does not demonstrably depart from Socrates in his fundamental understanding of the conceptual nature of morality. He does not explicitly deny the existence of any objective moral truth3. Rather he questions our innate ability to receive and act upon it. His point of departure then is seemingly more a matter of human psychology; it becomes a question of fortitude and of individual moral restraint which he acknowledges may be reasonably limited.

            He describes two akratic variants: unqualified and qualified, both of which are understood with reference to external objects that elicit sensations of pleasure or pain within the individual. To be “unqualifiedly un-self-controlled” is to be appetetively akratic with regard to “necessary” (NE1147b25), or what might be more usefully described as biological, pleasures,

…what relates to food and the need for sex, and in general the sorts of bodily concerns [that are] the sphere of self-indulgence and moderation…


            For Aristotle, unqualified un-self-control is the most shameful face of weakness of the will and the most deserving of moral censure because it represents the defeat of rationality and good judgement by unthinking physical need or desire. It is not necessarily characterised by immediacy, whereby a person reacts quickly and with little deliberation to being suddenly and forcibly overcome by the desire for such and such; one may indeed spend some time deliberating the best course of action but in the end still be overwhelmed by the sustained force of desire and the intellect is again defeated by the passions.

            Un-self-control with qualification is to be akratic “with regard to” (NE1147b30) something that is not merely biologically necessary but engages the intellect and is desirable in and of itself, things like

…winning, honour, wealth, and other such things that are good and pleasant…


One can be said to be weak-willed with respect to these things when one pursues them to excess,

…contravening the correct prescription that is in them…


            Lack of self control with specific regard to temper represents, for Aristotle, the least shameful and perhaps therefore the most forgivable example of weak-willed behaviour,

            For reason, or sensory appearances, indicate ‘unprovoked aggression’ or ‘insult’, and temper, as if having reasoned it out that this sort of thing is cause for going to war, moves into angry mode at once…


            Even if a quick, un-self-controlled temper that reacts to and attacks something distressing is misguided or misplaced, it still operates on some level within the sphere of reasoning. Such behaviour can rarely be described as simply animalistic. Our response to perceived danger is intellectual as well as physical in that it is not only our personal safety that feels threatened but moreover it is our distinctly human dignity that is affronted.

            As to the question of how it is that the knowledgeable, rational aspect of the soul can in fact be superseded by the non-rational elements involved in decision making, Aristotle explains the phenomenon by delineating knowledge into that of universals and that of particulars:

            …there are two ways in which we say someone knows… there will be a difference between doing what one shouldn’t when knowing one shouldn’t but not having regard to the knowledge, and doing it when actually having regard to it; for this is what is thought astonishing… Further, since there are two types of premiss, there is nothing to prevent someone from acting ‘contrary to his knowledge’ when he has both premisses but is using only the universal one, not the particular one; for it is particulars that are acted on.


            Universal premises might be thought of as general rules that serve to govern our moral behaviour. Particular premises are based on our perceptions of how things appear to be to us in the world around us. An example of a universal premise might be something like this: ‘High salt intake is detrimental to human health. I am human and therefore should avoid salt-rich foods in my diet in order to optimise my own good health’. Failure to act on one’s own good advice may be as a result of failing to recognise the universal in the particular; for example, one might assume that white bread is good, nutritious food and as such deem it unnecessary to investigate any further into its actual salt content which, in reality, is very high. In this instance, the ‘agent of action’ truly knows and understands the universal premise but does not ‘have’ or does not “activate” (NE1147a5) knowledge of the particular premise and therefore acts akratically with respect to indulging in an appetitive desire for white bread.

            Conversely, one may well grasp the particular premise but attach it to an altogether different universal premise. In the example of eating white bread, one might focus on the universal premise of, ‘The human body requires a steady intake of complex carbohydrates for energy and growth. I am human and therefore should include complex carbohydrates in my diet’. The action of eating white bread remains akratic in that the choice of universal premise to which one attaches the particular premise is ultimately driven by appetite. The choice of an alternative, low-salt, complex carbohydrate foodstuff still remains.

            Aristotle indicates a third way in which we may be said to have, but ‘not use’, knowledge and that is in the case of one being “asleep, raving or drunk” (NE1147a10) where, in such states of unreadiness for action, the individual cannot be said to even be in a position to form any meaningful connections between the universal and the particular.

            Additionally, knowledge of either sort of premise is proportional to time in that it is not enough to just learn it, as by rote, but one must also “assimilate it” (NE1147a20) in order to properly and more deeply understand it and therefore to ‘know’ it in the truest sense. In summary, occasions of weakness of the will, whereby an individual acts un-self-controlledly with respect to their own better judgement, despite knowing what the morally right course of action would be, are possible, according to Aristotle, because

            …the final premiss is both a judgement about something perceived, and what determines actions, either he does not have this because he is affected as he is, or he ‘has’ it in the sense in which we said ‘having’ was not a matter of knowing but only of talking, like the drunk with the verses of Empedocles.


            Aristotle’s considerably detailed attempt to reconcile the Socratic paradox of ‘no-one ever does wrong knowingly’ with the innumerable, observable instances of what appear to be akratic human behaviour (and seemingly by all – though to different degrees) in the end leads him full circle to a conclusion that, ultimately, supports Socrates’ logic:

            And because the last premiss is not universal and does not seem to express systematic knowledge in the way the universal premiss does, one also seems to get what Socrates was looking for; for it is not what seems to be knowledge in the primary sense that the affective state in question overcomes (nor is it this kind of knowledge that is ‘dragged about’ because of the state), but the perceptual kind. Let this much, then, stand as our treatment of the ‘knowing and not knowing’ aspect of the subject, and of the sense in which it is possible for someone to know and yet act uncontrolledly.


                        So, according to the Aristotlean analysis of the formal structure of weakness of the will, akratic incontinence becomes possible if we allow: firstly, that the soul exists as a compartmentalised entity with some kind of interface allowing intermingling of the thus separated rational and non-rational elements; secondly, that knowledge exists as a schematically tiered system rather than a single thing per se; and thirdly, that knowledge alone is insufficient motivation for action without the prerequisite disposition of character.

            Philosophic examinations with regard to epistemology or the nature of the human soul (whatever that might be) would be little more than distracting digressions at this point. The actual point of contention, for Socrates at least, is the notion that non-rationality plays any part whatsoever in our moral deliberations or decisions leading to action. He steadfastly maintains that

            …this ‘being overcome by oneself’ is nothing other than ignorance, and overpowering oneself is nothing other than wisdom.


            Because he does not consider it necessary to formulate any distinction between sophia and phronēsis or between knowledge and wisdom, together, they are, singularly,

            …most excellent of all human things.


            Furthermore, he regards enkrateia and akrasia as being nothing more than extremes of what he understands to be ‘moderation’, which itself fits within his description of knowledge:

            …if in fact it’s necessary that one thing have only one contrary and not more… and… that wisdom and moderation, in turn, appear to be contraries of foolishness, which is itself one… Would moderation and wisdom, then, be one?


            For Socrates, the thing which Aristotle calls akrasia or self-control and categorizes as a disposition of character is itself a species of knowledge which necessarily follows from human excellence. Non-rationality occupies mental space neither in the apprehension of moral truths, nor in the ‘all-things-considered’ deliberations that are appropriate to particular situations, nor in the resulting actions of the individual.

            Because this intellectualistic account is entirely self-evident to Socrates, he does not elucidate upon it. Contemporary philosophers have clarified his argument by restating it in the following way: It is an inescapable fact that we are biological entities with biological needs. It is also true that we possess and employ rationality. Biology and rationality are not warring factions in an entity that is thus cleaved into two, and biology is not synonymous with non-rationality in such terms as those described by Aristotle. An individual who is rational cannot be anything other than wholly rational. And reasons are the objects of rationality. Physical appetite, desire, fear and all human emotions are contingent states that provide us with reasons for acting in a particular way. But those reasons have to be considered in the larger moral context and weighted appropriately with respect to those more powerful reasons for action that are prescribed by the objective truth of what is morally right and good. Moral reasons overrule all others. Supposed akratic action is, more correctly, irrational action. Only thoroughly rational agents can be said to act irrationally and only through lack of moral knowledge.

            The division of knowledge is therefore crucial to the cohesiveness of Aristotle’s account of akrasia because he himself cannot accept that “primary” (NE1147b15) moral knowledge could be in any way subjugated.

            Neither Plato in his Protagoras nor Aristotle in his Nicomachean Ethics offers any illumination or exposé as to what ‘in actuality’ constitutes rational or objective moral truth or truths. It is beyond the scope of this essay to investigate to that end. Suffice to say that the existence of moral truth or truths within the fabric of objective reality, in whatever form, even if apprehended differently in each case, remains either unquestioned as a basic assumption or is otherwise external to the specific point of enquiry in both texts. Socrates intimates that it is his wish

…to investigate how in the world things stand in regard to virtue and what in the world virtue itself is.


His fullest investigation into the nature of virtue is reserved for Plato’s Meno and is not expounded to any satisfaction in Protagoras but he does at least hint at the direction his argument will take in posing the following question to his present interlocutor,

            …‘wisdom’ and ‘moderation’ and ‘courage’ and ‘justice’ and ‘piety’ – do these things, though they are five names, pertain to one thing…?


            He does not expressly or succinctly proffer the doctrine ‘virtue is knowledge’ in Protagoras, but his discussion with the sophist (with regard to the validity of sophistry as a means of moral instruction) leads him to a position where he is

            … attempting to demonstrate that all things are knowledge – justice and moderation and courage – in which manner virtue would most of all appear to be something teachable. For if virtue were something other than knowledge… it clearly wouldn’t be something teachable.


            Accordingly, if it is in fact the case that virtue can be reduced to knowledge then we may come to know it in the truest and fullest sense through rational reflection.  Thus, having acquired such knowledge, ‘no-one ever does wrong knowingly’.

            Assuming that objective reality is fundamentally consistent, there appears to be no error of logic in Socrates’ argument and the logical conclusion of that argument is that while ever we are in full possession of the moral facts we simply have no choice but to act accordingly. Our actions in the world, in real space and time as we understand it, are bound by logical determinism and our freedom to choose to do otherwise is simply illusory. Weakness of the will is logically impossible. The consequences for our wider moral lives, with respect to our daily interactions with other moral agents, are that we are not free to choose to behave immorally towards them nor they towards us, and if in any instance we do behave immorally then we necessarily do so unknowingly. Praise and blame become entirely inappropriate and effective moral correction must take the form of ‘rational instruction’ rather than punishment or retribution.

            Aristotle’s dichotomized soul and divided model of knowledge and reasoning appear, on the surface at least, to restore some degree of free will to the moral agent by allowing the individual the choice to do otherwise. On closer inspection, however, the freedom he purports to have wrung out of the amendments to Socrates’ model reveals itself to be the unfreedom of causal determinism in the form of biological impulses, the origin of which we have no control over. Aristotle does believe however that we can transmute the biological chain of causality by learning how to control and regulate our own emotions, thus modifying our own reactive behaviour by conditioning ourselves to be more self-controlled, or less akratic:

Excellence being of two sorts, then, the one intellectual and the other of character, the intellectual sort mostly both comes into existence and increases as a result of teaching (which is why it requires experience and time), whereas excellence of character results from habituation…


He straightforwardly asserts that

…we become just by doing just things, moderate by doing moderate things, and courageous by doing courageous things.


            This otherwise seemingly unremarkable line of thought leads Aristotle to a very curious philosophical conundrum in which it would appear that it is the intentions and actions of the virtuous themselves that define or reveal the truth about what is morally good:

…the things that come about in accordance with the excellences count as done justly or moderately not merely because they themselves are of a certain kind, but also because of facts about the agent doing them – first, if he does them knowingly, secondly if he decides to do them, and decides to do them for themselves, and thirdly if he does them from a firm and unchanging disposition… So things done are called just and moderate whenever they are such that the just person or the moderate person would do them… a person is not just and moderate because he does these things, but also because he does them in the way in which just and moderate people do them.


            Aristotle’s emphasis on disposition of character, both with specific regard to his analysis of the possibility of weakness of the will and with regard to his broader, general theory of ethics, brings him closer to the position of the virtue ethicist: a so-called more naturalistic approach to ethical theory where the extent to which we can be considered morally responsible or accountable for our actions is intimately tied up with our own personal upbringing and also the wider influences of the culture in which we find ourselves, neither of which, at least to begin with, as far as Aristotle is concerned, we have any control over.

            Aristotle’s overall theory is philosophically problematic for several important reasons. His notion of soul is fundamentally dualistic but he provides no clear or satisfactory account of how the mental and physical aspects interact therein. He clearly believes that the individual must live intellectually and morally beyond the biological infrastructure into which one is born but he offers no indication as to when one might reasonably be expected to achieve such intellectual and moral status and therefore rightfully be regarded as being morally culpable, or by what mechanism one might interrupt the forward flow of causal determinism. Neither does he offer any illumination as to how we might correctly ascertain the point at which one can be said to become responsible for one’s own learning and habituation, nor the point at which parents or teachers might reasonably stop being morally answerable for the actions of their children or pupils. His structure of knowledge, whilst deeply considered, remains arbitrary and he does not resolve the conflict that arises between what he calls ‘primary’ knowledge and his description of the virtuous individual, each as sources of and driving forces for morally right action. With respect to virtue ethics, he provides us with no clear indication as to how we might discern the greatest virtue between two virtuous persons acting differently in comparable situations.

            Despite these difficulties, Aristotle’s argument, to my mind, ‘feels’ closer to the subjective reality of good moral sense which, in the end, may very well result from an unfathomable amalgam of rationality and emotionality (and intuition and best-guess approximation), however philosophically untenable.

            Whilst there is an undeniable aesthetic quality to the intellectual purity to which Socrates aspires in his philosophy, when we hold it up as a mirror to real life, it becomes less convincing. The most strikingly obvious problem with the Socratic version of morality is that people don’t always (or even often) act in ways that we can clearly recognise as being an outward expression of any inner depth of knowledge of objective moral truth. If it is rationality which apprehends and acts upon moral facts then rationality, it would seem, is far from divided equally among us and even the most morally upstanding individuals occasionally lapse. Furthermore, it seems to be on more of an emotional level than an intellectual one that we respond to those digressions. Disgust and empathy are things that we ‘feel’ rather than ‘know’. Intellectual deficiency with regard to moral matters would appear to be depressingly widespread.

            Though Socrates prizes rational thought above all else, Aristotle does not conceive of the mind as existing in any meaningful or usefully separable way from the body in which it is essentially grounded.

            It is Socrates’ theoretical disengagement from what it really feels like to be a moral agent in this world that Aristotle is attempting to emend:

            …we are not inquiring into what excellence is for the sake of knowing it, but for the sake of becoming good, since otherwise there would be no benefit in it at all…


            Of course, the possibility that moral truths, as Socrates envisages them, may remain inapprehensible or unattainable to us does not in itself negate the possibility of their existence3. This is both metaphysically and psychologically important if it follows that, without them, we find ourselves stranded in a Dostoyevskian moral darkness where “everything is permitted”. It is precisely this moral void that St. Augustine sought to fill with moral revelation.

            Finally, if we take Socrates’ moral education and Aristotle’s character habituation to represent two sides of the same coin then we arrive at a place of convergence where we could, in this final quote, and without inconsistency to either argument, supplant Aristotle’s use of the word “habituated” with Socrates’ use of the word “educated”:

  So it does not make a small difference whether people are habituated to behave in one way or in another from childhood on, but a very great one; or rather, it makes all the difference in the world.




      1In the whole of Protagoras Socrates makes a single passing comment with regard to what he calls prudence. With respect to knowledge being a single, indivisible entity, “both noble and capable of ruling” (P352c), he adds that

…prudence is competent to come to the person’s aid[.]


It is clear from the context (and chronology) in which this reference to “prudence” appears that, for Socrates, the word is not pre-defined in terms of Aristotle’s phronēsis and the two terms are not synonymous. Socrates does not regard prudence as being a sub-category of knowledge or as having any sort of attachment to non-rationality and he does not use the word as such.

      2Socrates only once refers to “diligence” in Protagoras:

Previously I used to hold that it is not through human diligence that the good become good, but now I’ve been persuaded.


At first sight he appears to be using it in the same way as Aristotle but closer inspection reveals this not to be so. Whereas Aristotle uses the word “diligence” with respect to character development through habituation, Socrates uses it with respect to intellectual advancement as a result of honing one’s rational skills. It marks the turning point in Protagoras where Socrates concedes that virtue is, in fact, teachable. What follows is an investigation into whether it is the philosopher or the sophist that truly ‘knows’ virtue and therefore who is rightfully placed to teach it to the eager, young Hippocrates.

      3It need not be assumed that Aristotle or the historical Socrates conceived of anything approaching, or equivalent to, Plato’s eternal Forms.



Aristotle, Broadie, S. (commentary), and Rowe, C. (translation), Nicomachean Ethics (Oxford University Press, 2002).

Plato, The Republic, 2nd Edn. (Penguin, 2007).

Plato and Bartlett, R. C. (translator), “Protagoras” and “Meno” (Cornell University Press, 2004).