A Treatise of Human Nature

why do humans think and act the way we do? this question has been at the heart of philosophical inquiry since the beginning of history. 

in 1740, scottish philosopher david hume published his answer to the question – his famous a treatise of human nature. challenging the intellectual orthodoxy of his time, this seminal work dissects the murky realms of psychology and morality with scientific precision, arguing that humans are guided by passion over reason.

hume’s ideas sparked a philosophical revolution, influencing thinkers from kant to darwin. his skepticism about human reason and emphasis on emotion as a driver of behavior laid the groundwork for modern psychology. 

this chapter offers a quick but transformative journey into hume’s thought. let’s get going! 

where do our ideas come from? and why can we imagine a unicorn even though we’ve never seen one? these questions about the nature of human understanding have puzzled philosophers for centuries. 

at the heart of hume’s exploration of this question lies a revolutionary argument: all of our ideas, no matter how complex, ultimately derive from our sensory experiences. this means that there are no innate ideas independent from experience.

to understand this concept, let’s break it down. our mental content can be divided into two categories: impressions and ideas. impressions are our immediate, vivid sensory experiences – like seeing a red apple or feeling pain. ideas, on the other hand, are the fainter copies of these impressions that we use in thinking and reasoning. for instance, when you remember the taste of chocolate, you’re accessing an idea derived from past impressions of eating chocolate. 

this distinction leads hume to a crucial principle: every simple idea corresponds to a simple impression. you can’t have an idea of a color you’ve never seen or a sensation you’ve never felt. even our most abstract thoughts can be traced back to combinations of these simple ideas from experience. 

but what about complex ideas, like that of a unicorn – or our concept of justice? these are formed by combining and rearranging simple ideas from our experiences. we can imagine a unicorn by combining our ideas of a horse and a horn, both of which come from real impressions. 

the implications of this view are profound. it suggests that our knowledge is limited by our experience. we can’t truly conceive of anything entirely beyond the realm of what we’ve experienced in some form. this challenges the idea of innate knowledge that was prevalent in hume’s time. it also raises important questions about the limits of human understanding. 

however, this doesn’t mean our minds are passive receivers of information. we have the ability to combine and manipulate ideas in creative ways. our imagination allows us to form complex ideas and concepts, even if their components are always rooted in experience. that’s how we can form abstract concepts such as that of justice. 

this account of human understanding was revolutionary at the time – it was a challenging new perspective on the origin of our thoughts and beliefs.

there are few things we can be absolutely certain of in life. yet most of us would claim to know that the sun will rise tomorrow morning, or that water will boil when heated enough. but how can we be so sure? is it through logic, or something else entirely?

hume argues that our understanding of cause and effect, and indeed all reasoning about matters of fact, is not based on reason alone but on experience and habit. when we repeatedly observe one event following another, we begin to associate them in our minds. this association becomes so strong that we come to expect the second event whenever we see the first. for instance, when it's morning, we expect the sun to rise.

but – and this is crucial – we never actually observe the causal connection itself. we only see one event following another, not the "power" that makes it happen.

this leads hume to the conclusion that our belief in cause and effect relationships is not based on rational understanding, but on habit formed through repeated observation. we can't prove logically that the future will resemble the past, yet we constantly rely on this assumption in our daily lives.

this means that much of what we consider knowledge is actually probability based on past experience. we don't use reason or logic nearly as much as we think we do.

moreover, when we subject our reasoning processes to rigorous scrutiny, we find that they are fraught with contradiction and uncertainty. even mathematics and logic, often considered bastions of certainty, rely on assumptions that cannot be proven within their own systems.

our belief in the external world, in cause and effect relationships, and even in our own continuous identity over time – all of these, hume suggests, are based more on psychological tendencies than on ironclad logical proofs. this naturalistic understanding of human cognition challenged the foundations of rationalist philosophy, raising questions about the nature and possibility of knowledge that continue to be debated today.

this leads hume to the startling conclusion that total skepticism about all knowledge seems to be the only intellectually honest position. yet he recognizes that such extreme doubt is psychologically impossible to maintain. we cannot help but believe in the reality of the external world and the validity of our basic reasoning processes, even if we cannot ultimately justify these beliefs.

hume's resolution to this dilemma was a kind of mitigated skepticism. we should remain aware of the ultimate uncertainty of our beliefs, but continue to reason and act based on our natural inclinations and the lessons of experience. this approach allows us to engage in philosophy and science while maintaining a healthy humility about the limits of human knowledge.

alongside his novel take on human understanding, hume offers a groundbreaking theory on emotions. his concept of the double relation of impressions and ideas provides a unified explanation for how complex emotions like pride, humility, love and hatred arise in the human mind. 

hume believes that these emotions are not simple, irreducible feelings, but rather arise from the interplay between our perceptions and our mental associations. for an emotion like pride or love to occur, two elements must be present. first, there must be an object or quality connected to ourselves or another person – a relation of ideas. second, there must be a separate pleasant or unpleasant feeling produced by the object or quality – a relation of impression. 

this double relation generates complex emotion. for example, when we feel pride in our beautiful home, the house is related to us through ownership. this is the relation of ideas. at the same time, its beauty independently gives us pleasure. this is the relation of impressions. this double connection generates the feeling of pride. the same principle applies to humility, love, and hatred, with variations in the nature of the connections and feelings involved.

importantly, hume argues that this process happens through natural mental associations, not conscious reasoning. our minds automatically make these connections and produce the resulting emotions, which is why they can feel so immediate and powerful.

this theory elegantly explains why we can feel these emotions toward such a wide variety of things – our accomplishments, possessions, family members, friends, and even strangers with admirable qualities. as long as there's some connection to ourselves or others, and an independent positive or negative feeling, the emotion can arise.

hume extends this framework to account for more complex emotions like respect, contempt, and romantic love, viewing them as mixtures of the basic emotions in various combinations.

by breaking down these complex emotions into simpler components, hume's theory offers profound insights into human nature and our emotional lives. it provides a new lens through which to understand ourselves and our relationships with others, grounding our emotional experiences in the fundamental workings of the mind.

the question of what’s right and what’s wrong has puzzled philosophers for so long that they invented an entire discipline for it – ethics. 

hume changed the way this question was perceived. he argues that moral distinctions are not derived from reason alone, but rather from our feelings and sentiments. this challenged the prevailing view of the time that morality was based on rational principles or eternal truths discoverable by reason.

undeniably, moral judgements have a very practical effect on our actions and passions. we feel compelled to act in certain ways based on our moral beliefs. however, reason alone cannot produce actions or influence passions. therefore, moral distinctions must come from something other than pure reason.

consider how we judge a character in a novel. we don't rationally deduce that they're good or evil; we feel it. the same applies to real-life moral judgments. when we see an act of kindness, we feel approval. when we witness cruelty, we feel disapproval. these feelings, not logical deductions, are the basis of our moral judgments.

if morality were based on reason alone, it would have to consist of relations between objects that could be discovered by human understanding. however, we can find the same relations in situations we don't consider moral at all. for example, a young tree that grows to overshadow and kill its parent tree has the same relation of “killing its parent” as a person who commits patricide, yet we don't consider the tree's action immoral.

hume also famously cautions against deriving an “ought” from an “is.” no matter how many factual statements we make about the world, we can't logically derive a moral imperative from them without already assuming some moral premises.

moral distinctions arise from a moral sense – a feeling of approval or disapproval that we experience when contemplating actions or characters. this doesn't mean morality is arbitrary or purely subjective, but it does mean that our emotions and sentiments play a crucial role in our moral judgments.

hume’s perspective shifted our understanding of ethics from a search for abstract moral truths to an investigation of human nature and the sentiments that guide our moral judgments. it's a revolutionary idea that continues to influence how we think about morality today.

imagine a world without rules, where people could take whatever they wanted whenever they wanted it. chaos would reign, and society as we know it would crumble. clearly, humans need rules to form functioning, cooperative societies. 

hume argues that the concepts of justice, property rights, and the obligation to keep promises are precisely that – artificial rules created by humans to maintain social order and enable cooperation. they are not natural virtues, but arise from our self-interest and the necessity of living together in society. 

hume believes that humans are naturally selfish and have limited generosity. however, we're also intelligent enough to realize that cooperation brings greater benefits than constant conflict. this realization leads us to create rules that protect property and ensure fairness.

consider how we establish ownership. the first person to possess something is generally considered its owner. this “first possession” rule isn't based on any inherent moral quality, but on its simplicity and effectiveness in preventing disputes. over time, we develop other rules for transferring property, such as by consent or inheritance.

promises, too, are artificial constructs. we create the institution of promise-keeping because it allows us to cooperate and trade more effectively. when we make a promise, we're not expressing some innate moral feeling, but participating in a social convention that we've all agreed is useful.

government, according to hume, arises as a way to enforce these rules of justice. while small societies might manage without formal government, as societies grow larger and more complex, we need institutions to ensure that everyone follows the rules.

by understanding justice, property, and promises as human inventions rather than natural laws, we can see how flexible and adaptable our moral systems can be. this perspective helps explain why different societies might have different rules, and why our own sense of justice can evolve over time.

this chapter to a treatise of human nature, by david hume, introduced his classic theory of human understanding, sentiment, and morality.  

hume's groundbreaking work challenges traditional views on human nature and knowledge. he argues that all our ideas ultimately derive from sensory experiences – we possess no innate knowledge. at the same time, our reasoning is based more on habit than reason, leading to skepticism about absolute certainty in knowledge. hume proposes a theory of emotions arising from a “double relation” of impressions and ideas, explaining complex feelings like pride and love. he also argues that morality is grounded in sentiment rather than reason, and that moral judgments stem from feelings of approval or disapproval. finally, hume contends that concepts like justice and property rights are artificial constructs created for social cooperation, not natural virtues. his revolutionary ideas laid the foundations for modern empiricism, psychology, and moral philosophy.

okay, that’s it for this chapter. we hope you enjoyed it. if you can, please take the time to leave us a rating – we always appreciate your feedback. see you in the next chapter.