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Key Concepts of the Philosophy of David Hume


David Hume was an 18th century Scottish philosopher, who after John Locke and George Berkley is considered the third major empiricist philosopher of the modern era and easily the most radical. Empiricism is the epistemological position that all significant knowledge comes from the senses. Hume was so fascinated by the claims of Locke and Berkley that he pushed this concept to the extreme and consequently left all modern philosophical thought in complete disarray. Hume’s empiricism destroyed the idea that human beings could have any real knowledge about anything and proposed that our senses were the only thing that we really know and therefore was the only reality we could have any knowledge about. While Hume attacked the ideas put forth by rationalists like Descartes he did not give Locke or Berkley a free pass and made many devastating criticisms of them as well. While Hume found religion to be nonsensical he didn’t allow science to get by without taking a number of substantial blows to its claim to knowledge either.


Despite being a destructive force in late modern era philosophy, Hume was well known for being a likable and easy to get along with person. This is a sharp contrast to most major philosophers who had tumultuous relationships with those around them and many are well known for eccentric, if not outright anti-social behaviors. Despite publishing his great work, The Treatise of Human Understanding, at the age of 24,Hume was not able to secure a regular teaching position because he was long suspected of atheism, a belief that he made no effort to dispel, and his later unpublished writings showed that he in fact held. Hume was still able to make a living by writing a popular history of England book series and though The Treatise of Human Understanding was never a popular success he was able to publish a much shorter summary of his ideas in The Enquiry Concerning Human Understanding that was more popular with the public.

Radical Skepticism

Hume contended that all knowledge could be divided into two categories, Impressions and Ideas. Impressions were vivid perceptions that we could not be wrong about. Examples of Impressions would be color sensations, such as seeing the color yellow, and emotional responses such as being angry. Ideas, to Hume, were when we reflected on our Impressions. Our memories of seeing the color yellow or of being angry would count as Ideas and he contended that we could be wrong about them. Hume insisted that the mind could not generate any ideas without first being exposed to an Impression upon which to base it on. Well, sort of. After making this contention Hume then goes on to give a counter example to his own argument. (?!) He states that if a person had a perception of two separate shades of blue that they may be able to generate the Idea of a shade of blue that was in the color spectrum between these two separate shades of blue without first having the Impression. Why Hume would give such a devastating counter example to his own argument is a mystery but I prefer to think that he was on such a skeptical mission he couldn’t help but be skeptical to his own ideas.

Hume takes the ideas of everything coming from Impressions as far as he can. He developed an idea called “Bundle Theory” which states that no actual objects exist, just a bundle of Impressions of that object. Hume took this as far as suggesting that there is no actual self. What we perceive as ourselves is actually a bunch of sensory data that we use to perceive the Idea of the self. To prove that objects are just a bunch of Impressions, Hume asks you to imagine an object with no Impressions (color, shape, smell, taste etc.) and realize that there is nothing left. His claim that this extends to our ideas of self flies in the face of the philosophy of René Descartes, who had claimed in his own philosophy that the self is the one thing that could not be in doubt.

Hume claims that all of our complex ideas are made up of simpler ideas combined. Our concept of God is an example of this. We imagine a supremely perfect being made up of our ideas of justice, goodness and intelligence. Hume states that our ideas are essentially faint, obscure and easily mistaken while our impressions are vivid and real to us. This is his principle criticism of rationalism, which believes that important knowledge can be obtained a priori. (before experience.)

Cause and Effect

Hume is responsible for the observation that “correlation does not equal causality” which we now often hear stated in the sciences and encourages us to be skeptical of claims that events that occur together have causal relations. Hume draws a distinction between relations of ideas and matters of fact. Relations of ideas are things that are self-apparent. These include 2+2=4 and All Bachelors are Unmarried Men. These relations of idea are true by definition. All one must do is understand the relations of ideas to know the truth of the statements. Matters of fact come from experience. If we go for a walk and the sun is shining on us this is a fact.

Hume becomes concerned how we infer one thing from another through our observations. If we see a swan, and every time we see a swan it is white, then we make the inference that “All Swans are white.” This is not a certainty. We could see a black swan and find that while our experience has led us to believe that all swans were white we are in fact mistaken. Hume goes on to say that no amount of experience could possibly lead to being certain of a relation of cause and effect. Some philosophers have claimed that Hume is stating that cause and effect does not exist. (Kant takes big issues with this.) Others say that Hume is merely pointing out that there is something that we are missing when we infer a causal relation and can never verify through experience.

Hume’s claim seems to imply that inductive logic is essentially not really logic at all. It also causes major problems for the sciences but though scientists have taken note of this problem the use of the scientific method seems to still be the best method of obtaining useful knowledge and predicting outcomes. Hume himself believed that science was the best way to obtain knowledge but he was still concerned with the inability to infer cause, when using scientific methodology, with any certainty.

Free Will and Ethics

Hume was of the belief that free will and determinism were compatible with each other. What this means is that even though Hume believed that human actions were predetermined by physiological properties he thought that human beings were still free as long as they were allowed to act on these properties with their will not being infringed by outside forces. So basically Hume judged a person free if they were allowed to do as they wished and if someone were to infringe upon those wishes by stopping the person physically then the person was no longer free.

Despite holding this viewpoint on free will, Hume strongly objected to the ethics of Thomas Hobbes that all ethical actions were correspondent to the laws of science. Hume's primary objection to an ethics that corresponded with natural science is known as the "is/ought fallacy." Hume's claim proved that, logically speaking, an "ought" (moral claim) could not be derived from an "is". (matter of fact) Hume found Hobbes to be an egoist, a contentious claim, and he dismissed his ideas as being incompatible with the ways that human beings actually behave. Hume also dismissed the claims of natural law ethics held by the majority of theologians at the time and as proposed by St. Thomas Aquinas. Hume thought that ethics were essentially non-existent when relying on a physical explanation or a supernatural explanation but that a basis could be found for ethics by examining human nature.

Hume claimed that there is an inherent ethical component to the way human beings interact and we know ethical and unethical behavior simply by observing it and without the use of reason. In this way, he was one of the first to make the claim explicitly that human moral actions are based on inherent intuitions. Hume claimed that those who could not judge moral actions were “morally blind” just as somebody who does not see color is color blind. This viewpoint on ethics would have a huge influence on Utilitarians, such as Jeremy Bentham and John Stuart Mill, and would inspire Immanuel Kant to seek objective ethics based on reason to rebut Hume’s claim.


Robephiles (author) on June 16, 2011:

It is a puzzling problem for ethics. If somebody solved it at this point I would be very surprised.

cbl2988 from Mesa, Arizona on June 16, 2011:

It seems to me that deriving an "ought" from an "is" is logically impossible, unless, like you inferred, someone can change the way that we think of language. But I don't seem to fancy linguistic analysis very much... I don't know if they (linguistic analysts)could get the job done anyway.

Robephiles (author) on June 16, 2011:

There are still people who think it can be done but the vast majority of philosophers think the three theories that we have now are the best we are going to get. If a philosopher solved all the problems that are left they would be instantly proclaimed one of the greatest minds in history.

cbl2988 from Mesa, Arizona on June 16, 2011:

Does philosophy ever see a possibility of deriving an objective ethics?

Robephiles (author) on June 16, 2011:

Not completely. He comes pretty close but he has to make one assumption (value of humans) to get there. Also Kant's ethics aren't perfect. There are flaws here and there that need to be addressed. If you ever get the chance read Phillipa Foot's the Problem of Abortion and the Docterine of Double Effect. It is one of the best philosophy papers on Kant's ethics and the problems with it being objective.

cbl2988 from Mesa, Arizona on June 16, 2011:

I assume Kant never derived an objective ethics?