The Birth of the Enlightenment: John Locke’s An Essay Concerning Human Understanding

During my first year in college, I took an intro philosophy class.  It was the first and only straight philosophy class that I took in college.  Back then philosophy seemed too removed from the real world – a feeling I had about the rest of school, really, but philosophy even more so – it just seemed like a bunch of people sitting around a table and haggling about semantics.  What was the point?  

I’ve often wondered about people whom I’ve read and heard since then who described having an awakening in their first philosophy class in college.  It makes me think that perhaps these people must have entered college with some already strong questions about the world that they wanted to answer, or strong convictions that they wanted to prop up, or strong aversions that they wanted to investigate, to argue back against, to refute.  I remember well one young man in a class of mine on literary theory who really came alive when we were discussing Michel Foucault’s concept of the “deviant.” You could tell there was something there for him — and I’ve often thought that coming into college with some pet “concern” or “issue” with the world is not a bad thing at all — but a spur to inquiry and investigation — almost better than walking onto campus with the classic wide-open mind and lack of preconceived ideas.

What’s interesting though is that even though I was not drawn to philosophy classes, I was drawn to political philosophy.  Although I didn’t major in it, given the number of courses I took in it, I easily could have – or at least minored. This is curious because wasn’t particularly political: I had no interest in running for office, or even in working in government or in law (as many of my friends did); and I really had no particular interest even in following politics. I didn’t vote until I was out of college, when my time at a slightly corrupt, slightly “unjust” workplace suddenly woke me up (forgive me the metaphor!) to the political (if I only I’d had this experience just before college). Yet it’s almost impossible for me to recollect just how aloof I was from the combative, turbulent issues of the just-post-9/11 world in my early 20s. It was strange, then, that I drifted toward Plato, Aristotle, and the like. 

In retrospect, I can see that I have always been fascinated by the interplay of theory and practicality.  The notion that the workaday machinery of daily government – both the systems themselves and our own ideas about how to use them – are informed by intellectual theories, sometimes thousands of years old, was and is fascinating to me.  This is really the same intermixture of the material and the theoretical that fascinated me about — don’t laugh — the main passion of my life (God help me) during college: whitewater slalom kayak racing. Racing really embodied the idea of trying to apply a logical, rational plan and a well-developed, highly technical skillset to an inherently complex, chaotic, and ever-changing reality, all geared toward an eminently practical purpose (arriving at the finish line ahead of others), and requiring a thrilling mixture of rational technical preparation and on-the-fly decision-making and improvisation. 

And it’s surely the same thing that captivated me later on (once I’d washed the racing out of my system) about my true field, education, and which, years after I’d learned the practice, sparked my interest in the philosophy of education.  It turned out that I was the sort of student who needed a practical, real-world pursuit in front of him — if not a problem with the world, then at least some real reason that any attendant ideas or theories would be relevant and put to use before he’d start listening to the philosophers.

It is only now, in a sense, having run through the more narrow fields of political and then educational philosophy, that I find myself drawn back to where I first started and first took a pass: That same basic, bread-and-butter Western philosophy that I first encountered when I was 19. But now I confront this same material with real practical concerns and questions to ask — all driving me to learn and to investigate it as I surely never did back then.

And it is with this new set of eyes that I recently opened up my old college copy of John Locke’s An Essay Concerning Human Understanding, the first book we studied in that introductory philosophy course.  The fact that I know this because I saved not only the book, but the syllabus as well, indicates that perhaps somewhere deep down, I knew I’d need another pass through this material someday, once I’d found my true calling. I was right — I do. As I’ve written many times before, it has been the chaotic and turbulent era that we’ve been living in that has pushed me as an educator to try to better understand just what it is that our educational system should be aiming toward.  I recently studied John Locke’s famous educational treatise, Some Thoughts Concerning Education, and now it’s time to turn myself toward arguably his most famous work, the one I read first back in the winter of 2001: An Essay Concerning Human Understanding.

My Framing: Jonathan Rauch

I should mention at the outset that my understanding of this book has been very much framed by Jonathan Rauch’s recent book, The Constitution of Knowledge, which frames Locke as essentially creating the epistemology of modern liberalism – to paraphrase Rauch, booting out claims about reality that are not “checkable” in favor of empiricism.  For Rauch, Locke was framing the creation of knowledge in a wholly new way.  Knowledge is not innate in us, nor does it derive from revelation (at least not revelation that cannot square with our senses or reason), and it cannot come from maxims or general theories.  Instead, it comes from an empirical study of an objective, observable reality.  Okay, here’s the real quote I referenced above:

“What Locke was doing, here, was expelling from intellectual respectability – from the epistemic rulebook – claims which, because they are not checkable, are not adjudicable” (55).  This, for Rauch, includes all of the theological disputes of Locke’s era, the wars and battles fought over who was right – all done without any objective standard for adjudicating these claims.  Rauch claims that for Locke, this translates into the necessity of toleration, and even of welcoming diversity of opinions, with the notion of getting to the bottom of who exactly is right, and thereby advancing knowledge.  

Going into Locke, it was this framing I had in my head, and I was curious if this understanding would be confirmed, or whether there would be some other understanding I should take from Locke, or something else entirely.

Books 1 and 2: Locke’s Combativeness

It’s hard to tell just who Locke is responding to in Book 1 of the Essay.  In this section, Locke takes pages and pages to dispense with the notion that we humans are born with innate ideas.  Even the Golden Rule itself – seemingly the most sensible, innate idea that all humans share in their understanding, is suspect.  Locke’s reasoning is that because these rules must be explained to those who don’t know them, that someone knew to the idea would need an explanation and would not accept the rule as immediately self-evident, this is proof that these ideas are not innate.  Much of Book 1 follows this pattern, as Locke throws out a number of supposedly innate principles and ideas using this same logic.  In general, I found his reasoning along these lines somewhat suspect, and it was hard to know just who he was arguing against (I have read that Locke has been accused of straw-manning his apparent adversaries in this section).  Still, my basic feeling is that Rauch is generally correct in his interpretation of this section – Locke is shooing away the notion that truth is settled, innate, and instinctive within us.

The real “meat” of the Essay is Book 2, where Locke turns to his own positive description of how we acquire ideas.  It was hard for me to read this section without thinking just how out of date Locke’s ideas about the mind’s workings really are – there have been so many developments in cognitive science and the like in the 230 years since – and frankly I found myself skimming over whole long sections in this part.

What interests me more, of course, is Locke’s two-fold overall project:  First, the way that his alternative account of understanding creates a whole new epistemology (per Rauch), and secondly, what political and humanistic ramifications this had in the creation of the Enlightenment.  

Locke of course, starts the book by writing that his goal is a humble one – simply to understand what human beings can and cannot know.  As I got further into the book, I began to see the parts where Locke’s overall mission makes itself even more clear.  

For starters, I always thought that Locke was a dry, sober figure – a patient observer like Aristotle.  But he’s not – clearly he’s combative and direct, given Book 1, and partway through that book, there’s a fiery passage where Locke lays out his real mission.  Too many people take things on faith, rather than examining them for themselves.  They take “things upon trust, misemploy their power of assent, by lazily enslaving their minds to the dictates and dominion of others, in doctrines, which it is their duty carefully to examine; and not blindly, with an implicit faith, to swallow” (104).  Locke even extends this to the knowledge of God, which he says men must examine for themselves, rather than simply getting their understanding from others. Locke quickly addresses the claim that he is “pulling up the old foundations of knowledge and certainty” by arguing that his method, the empirical way of each person inquiring for himself actually “lays those foundations surer” (105).  Moreover, this empirical inquiry will not only make each man surer of his understandings, but it will advance knowledge: “I hope it will not be thought arrogance to say, That perhaps, we should make greater progress in the discovery of rational and contemplative knowledge, if we sought it in the fountain, in the consideration of things themselves; and made use of our own thoughts, than other men’s to find it” (105).  Locke’s advocacy of empiricism reminds me of Martin Luther’s push for individual humans to establish a more personal connection with God; Locke’s view is explicitly anti-authoritarian and individualist; it is only the rational, empirical investigation of each individual person that counts.  We should just as soon try seeing with another’s eyes, he writes, as to take their word for it concerning important truths.  There is no substitute for understanding things for ourselves: “What in them was science, is in us but opiniatrety” – what a great word! – “whilst we . . . do not, as they did, employ our own reason to understand those truths, which gave them reputation” (105).

Here is where Locke mentions names.  Although Aristotle was a fantastic philosopher, we should emulate his approach, rather than simply accept his findings as a matter of faith.  He was not considered wise because he “blindly embraced, and confidently vented the opinions of another” (105).  This is where I began to get the sense that Locke was talking back to the Aristotelian-Christian-scholastic tradition, who Locke appears to derive as “those who affected to be masters and teachers” (106) and who offer past notions of truth to be swallowed uncritically and thereby put them in a “posture of blind credulity, [in which] they might be more easily governed by, and made useful to some sort of men, who had the skill and office to principle and guide them” (106).  In other words, Locke is telling us that the concept of innate ideas not only “eased the lazy from the pains of search” after new truth – and stunted further understanding – but also made sheep of ordinary people, made them easy to govern and to manipulate for their own purposes and power.  This is stronger stuff that I had expected from Locke!

And here, for the first time, I’m starting to the see the fire of the early Enlightenment – the passion for breaking out of the established traditions, out of the established social positions of entrenched authority:

“Nor is it a small power it gives one man over another, to have the authority to be the dictator of principles, and teacher of unquestionable truths; and to make a man swallow that for an innate principle, which may serve to his purpose, who teacheth them” (106).  

Here Locke is pointing the way toward a new, exciting time in which the individual could determine things for himself, and thereby, it is implied, control his own destiny in a whole new way:

“Whereas, had they examined the ways, whereby men came to the knowledge of many universal truths, they would have found them to result in the minds of men . . .  discovered by the application of those faculties, that were fitted by nature to receive and judge of them” (106).

There it is, folks – the birth of the Enlightenment, or at least the seeds of it – a revolution in thought.

Book IV: Where Things Really Happen

If Book 1 has some fire to it – the fire of the start of the Enlightenment – then Book 4 is where Locke makes his revolutionary project explicit: he is, as Rauch described, pushing out claims that are not adjudicable.  But it’s not just the lazy, received wisdom of “innate ideas” promulgated by the Scholastics that he’s after – it’s the very notion of revelation itself.

Revelation is an anachronistic topic.  I had learned in college about the ancient tension between reason and revelation, but by the 21st Century, the debate surely seems settled.  Revelation as a foundation for knowledge is absolutely nonsensical.  It would be beneath reproach nowadays for someone to claim that theirs was real knowledge because they had a vision from God.  But we have to keep in mind that back in the 17th Century, this was commonplace, and it was the genesis of so many creed wars that had a ravaged Europe during the Medieval period.  Given this context, and given the power of revelation and Christianity for more than 1,000 words, I can imagine how revolutionary Locke’s Essay was when it was published, and I can imagine no aspect was more controversial than his extended attack on revelation in Book 4. 

Locke does not attack revelation directly.  Instead, he argues that one major cause of conflict in the world has been a lack of clear boundaries between reason and revelation – what can be known according to each, and what is the proper place for each – and he endeavors to clarify this boundary.  Locke argues that revelation cannot be admitted as truth on its own – it must be checked by reason.  He does this via an interesting two-step solution.  The first step is that he admits that what he calls “true” revelation – that which truly comes from God (as opposed to “traditional revelation” that comes from one who claims revelation) – does represent truth.  However, in the second step, this revelation must be checked by man’s reason in order to ensure that is empirically true – otherwise it would not truly be sent from God.  This is a fascinating formulation – and it is hard not to wonder if this is Locke’s way of slipping in his revolutionary, historic attack on the veracity of religious claims via a less offensive, apparently deferential method.  Locke even several times makes the claim that this is what God would want – that God is surely put off by the extravagant, wrong-headed claims of false preachers, and that God gave us reason specifically to check whether our revelations were truly from him: “God when he makes the prophet does not unmake the man.  He leaves all his faculties in their natural state, to enable him to judge of his inspirations, whether they be a of divine original or no” (621).  

But make no mistake, Locke believes that reason must have the final say over revelation at all times: “Reason must be our last judge and guide in everything” (621).

Again, this seems to me – from my admittedly limited historical understanding – to be a major moment in the birth of the Enlightenment.  Here is a philosopher telling us that revelation, which has carried the day since the fall of the Roman Empire, is in fact impermissible, and that the authority of the church, of the dogma and orthodoxy long reigning and unquestioned, is to be put underneath the authority of merely the powers of reason of each individual person.  

Moreover, Locke writes some scathing passages about why human beings pretend to have revelations – Locke calls this state of strong personal belief, often advertised as divine revelation, “enthusiasm.” Revelation is a quicker way to establish one’s opinions as truth compared to “the tedious and not always successful labour of strict reasoning” (616); “the ease and glory it is to be inspired and be above the common and natural ways of knowledge so flatters many men’s laziness, ignorance, and vanity” (617).  Locke actually uses the word “pretend” to describe some of these revelations – which must surely have been scandalous at the time (though surely every one with half a brain had seen it many times):  “It is no wonder that some have been very apt to pretend to revelation, and to persuade themselves, that they are under the peculiar guidance of heaven” (616).  This “crying up of faith” will continue to lead to “absurdities” which “possess and divide mankind” (614), with dangerous consequences. 

And this is where Locke’s political philosophy begins to shine through: toleration.

With his notions of true knowledge as understood via empirical inquiry, Locke is taking aim not just at the authority of the Church, but at the notion of certainty.  The flip side of beginning to rely on observation and reason, as Locke indicated, is that it’s hard work – a lot harder than just taking accepted wisdom as true, or pretending to revelation and insisting that you’re right.  Actually working your way through different problems is a lot harder, and more frustrating – because, according to Locke, we humans are limited in our amount of true knowledge.  We possess “liableness to error” (576) and our ignorance is “infinitely larger than our knowledge”; due to necessity, we must often rely on what Locke calls “probability.” 

Given our predilection toward error, and the challenge of discerning truth via observation and reason, Locke argues for epistemic humility.  Because “the greatest part of men, if not all” have mostly “opinions, without certain and indubitable proofs of their truths” – and because it’s unlikely and unreasonable to expect that in arguments one man is going to simply give in and concede the other’s argument entirely, we should be okay to, in the modern phrase, “agree to disagree.”  Locke writes, “It would, methinks, become all men to maintain peace, and the common offices of humanity, and friendship, in the diversity of opinions” (582).  We should, if we wish to convince others, present our arguments according to reason, and then give our adversaries time and space to reason through them themselves.  If this person is not persuaded, we should be okay with that, and not try to force our beliefs on anyone else.  

Moreover, we should practice not only epistemic humility, but collective inquiry toward a better understanding.  We should “endeavor to remove” our mutual ignorance “in all the gentle and fair ways of information” – which is to say through reason and observation – in order to “spend the days of this our pilgrimage with industry and care, in the search, and following of that way, which might lead us to a state of greater perfection” (576).  This, to me, seems like another creed of the Enlightenment forming: the notion that through rational inquiry and study of reality, we can better know truth, and therefore improve our earthly state.

And if there is a strongly individualist streak to this inquiry – that individual humans can know the truth better than great and massive authorities, whether political, religious, or historical – there is also a universalist implication that Locke is developing as well.  Locke is frustrated by the notion that because men do not or cannot pursue truth in an empirical fashion, they are chained to the caves of ignorance of their particular country.  He laments that every country may have its own “licensed guide,” each of whom has its own mistaken version of knowledge: the “oracles and standards of truth, which teach one thing in Christendom, and another in Turkey” (624).  Locke again subtly equates the development of truth with development and with happiness, which he believes suffers when men are trapped in their particular – ignorant – circumstances: “Or shall a poor countryman be eternally happy, for having the chance to be born in Italy; or a day-laborer be unavoidably lost, because he had the ill luck to be born in England?”

But to those men who would stand in the way of this progress toward the truth, Locke issues a clear warning: get on board, or prepare to fall behind.  It is once again a reminder of Locke’s anti-authoritarian streak that he aims this critique at the upper class.  He warns them that their social rank and status are no match for knowledge, and he insinuates that with the development of more empirical methods, society will progress to the point that the power of the upper class itself will be in great jeopardy.  He warns “those who call themselves gentlemen, that however they may think credit, respect, power, and authority the concomitants of their birth and fortune, yet they will find all these still carried away from them, by men of lower condition who surpass them in knowledge” (626).  There are two major assumptions here: the first is that knowledge, in Bacon’s famous phrase, is power.  The second is that the advent of the rational pursuit of truth, the very social fabric of the hierarchical society will be upended.  These are certainly revolutionary aspirations on Locke’s part.  History has borne out just how right he was.


Well, it’s all there, isn’t it – the birth of the Enlightenment?  In this magnificent book you can see the seeds of a seismic event in history.  All of the elements are there: the newfound focus on individual humans being able to use their innate powers of reason and observation to understand nature and objective reality with far greater certainty.  You see a corresponding focus on individualism: the power of the individual to question and indeed overturn the received wisdom of traditional authorities, including the church.  You see a budding element of universalism, embodied in Locke’s implicit call for the sharing of understanding across borders.  You see an increased focus on reason rather than revelation as the final arbiter of truth.  You see an implicit sense that individual human beings have the power to shape their own lives and their own happiness; you see earthly happiness, aided by the progress of knowledge, begin to take precedence as the key aspiration, rather than eternal or spiritual salvation.  You see the notion that knowledge equals both power and progress – and the implicit promise that more knowledge will can not only lead us to conduct our lives with greater certainty, but can begin to improve the material conditions of human beings.

In short, you see a great deal of confidence in the rational pursuit of an objective reality to help human beings understand the world, to improve it, and to improve their own lot in it.

And you can also see the seeds of Locke’s liberalism – the liberalism that so shaped the American founding – implicit in this too.  You can see Locke’s dedication that because humans are so liable to error, and truth so elusive, the toleration of divergent opinions, and the abstention from the desire to impose our views on others, is the only moral position.

It’s interesting that this book is most famous for two phrases – neither of which appears in the book: tabula rasa, and blank slate.  Locke never used either phrase.  Instead, he compares the mind to a bare cabinet, and to a blank sheet of white paper.  And what’s even more interesting is that Locke is not actually implying that there is nothing innate in human beings.  Many times he says that human beings do possess certain innate tools – but they are what he calls “faculties” – the ability to reason, the ability to observe through our senses – rather than innate ideas.  He also strongly implies that there does very much exist some stable notion of human nature: humans are apt to be selfish, lazy, to covet power, but also to hunger after truth and knowledge, and that they are capable of reasonable discussion and even toleration.  Locke is surely not a modern social constructivist – an extreme blank slater who believes humans are born as pure putty, with no innate faculties or predilections.  Locke isn’t try to dramatically reshape humanity by stuffing them full of new and revolutionary ideas in the cradle – he is merely trying to shake them awake and get them to exercise their natural, God-given powers of individual reason and observation.  He is trying to get them to use their native faculties; his “blank slatism” is more a desire to combat a fraudulent notion of received wisdom than the notion that humans are not infinitely malleable.

This is a revolutionary book – Locke is taking on a lot.  I am sure he was not the first, and surely not the only, but his contribution to the shaping of the Western tradition was clearly tremendous.  As I wrote before, Locke is a much more fiery writer than I imagined – much more combative.  He couches much of his revolutionary positioning in a fairly conventional Christianity, which as I’ve mentioned makes me curious to what extent this was a conscious strategy, or just Locke’s true belief.  But overall, I have heard this book called the most impactful book of philosophy since Aristotle, and after a thorough reading, I have to agree.  

I’m glad I saved this book from college, and I’m glad I returned to it.  There is so much more here of importance than I could have understood when I was 19.  Now I have practical concerns that drive me to understand history, and to understand where we came from.  This sort of continued drive after truth and understanding I think Locke would approve of.

Next I plan to turn to Locke’s political theory.  This man was something else, wasn’t he?  Not just a revolution in epistemology and understanding, but I am sure there are many who would say that his even greater contribution was in his outlining of modern liberalism.  Now, knowing his underlying ideas of truth and knowledge and meaning, I’ll turn to reading his classic political work, Two Treatises of Government.