David Hume was born in Edinburgh, Scotland. He studied Law first at Edinburgh University. Hume worked as a secretary, a librarian, and an embassy-personnel. David Hume went to France twice. He got acquainted with Jean Jacques Rousseau, Diderot, d'Hollbach, Turgot, and d'Alembert. When Rousseau came to England and looked for a job. Hume helped Rousseau to get a job, which Rousseau could not hold on to because of his prosecution complex.

Treatise on Human Nature
Book I of the Understanding
Book II of the Passion
Book III of Morals 1739-1740

1. Essays, Moral, Political and Literary 1741-1742
2. Enquiry concerning HUman Understanding
(=The Rewrite of Book I of Treatise) 1748
3. Enquiry concerning the Principle of Morals
(=The Rewrite of Book III of Treatise) 1751
4. Political Discourse 1752
5. Four dissertations 1757
Dissertation on the Passions
(=The Rewrite of Book II of Treatise)
Natural History of Religion
Natural History of Tragedy
Natural History of the Standard of Taste


David Hume attempted to improve John Locke's epistemology on the basis of Berkeley's radicalization of empiricism. The most important step in Hume's philosophy was to be found in his endeavor to discover what is given to our consciousness through our senses. Locke for example implied far more in its content than Berkeley and Hume was far less discovering in its content than Berkeley. Naturally, the way in which the philosophical questions were raised is far more radicalized by Hume such that nominalism was pushed to its extreme. In other words, according to Hume what is to be found in the experience is no other than sense-data. Berkeley indeed called them "sensible things." Instead of admitting something like unity, Hume described the same phenomenon a bundle of ideas. According to Hume, we cannot discover such a thing as unity, such relation as the liner, mechanical causality, etc., in those impressions or sensible things. Besides, it is not necessary to assume such a thing as unity beyond what is immediately given to us in our experience. As a philosopher, Hume believed that he must be satisfied with what is really known and it was his task that all those universals such as substance, unity, identity, relation, causality, are to be explained by some psychological law. In other words, Hume believed that we did not need all these universals, too, besides they were not known to us through our sense-data. Hume did apply literally Occam's razor (nominalist's approach to eliminate all the universals) to the question of the universal. Now, it is important to make his position intelligible such that he not only accepted everything we experience as it is, but also he did not believe anything behind what we experience. In other words, what we call something to be known by senses is pure sense-data and beyond these immediately given, Hume did not recognize anything else as the object of our knowledge. In this sense, Hume's attempt was to explain by psychological laws what was previously considered to be given in our ideas.
Furthermore, Hume did not allow us to apply the concept of "knowledge" to natural sciences. Hume distinguished between the relations of ideas, which we now call analytic knowledge, and the idea of matter of fact, which we now call synthetic knowlwedge. The analytic, or a priori knowledge and lthe synthetic, a positeriori knowledge have two different criteria for truth. While the knowledge about relations of ideas (such an a priori, analytic science as arithmetic, geometry) uses the principle of contraditicion as its principle of truth, the knowledge of matter of fact (=synthetic, a posteriori knowledge) needs to appeal for the criterion of truth to our sense experience and anything we recognize as a matter of fact, how universal it may appear, can in principle be false and thereby does not involve in a contradiction. Hume called our knowledge of relations of ideas alone "knowledge," while our knowledge obtained through our senses, our kknowledge of matter of fact, is called "opinion" and did not allow it to be considered "knowledge."
Thus, from the viewpoint of Hume, there is no foundation for us to recognize substance, which is the ultimate unit of reality since Descartes, nor the efficient causality as the principle of reality. Here all the natural sciences including the Newtonian mechanics face a threat that all these sciences are denied its universal and necessary validity as sciences and become mere opinions.
Started with Descsartes' absolutely certain knowledge of self's existence and the universe trhough Spinoza, Leibniz, Locke and Berkeley, the Contemporary Western philosophy must now face a challenge of Hume's ultimate skeptical position that no universe (=nature) is not only unknown to us, but also is not necessary for us to have our mundane everyday experience. The central concept of substance of the Contemporary Western philosophy has been completely "eloded" finally at Hume and, according to Hume, even the efficient causality which had been considered the absolute, indudbitable principle of reality is now questioned and unnecessary as to its reality.
Immanuel Kant's philosophy was allocated in such a spiritural, intellectual crisis of the natural sciences and philosophy. That is, the contention that no universal, necessarity knowledge is possible about the universe (=nature), was the outcome of Hume's philosophy.
Thus, Hume's philosophy has two extremely significant elements. On the one hand, Hume's viewpoint and consequences of his philosophy are an enevitable radicalization of the phlosophy of consciousness. It is indeed the deadend street. On the other hand, by destroying many traditional dogmas, Hume opened up a new possible way of doing philosophy, i.e., the transcendental philosophy, even though his successor, Kant, remained also in the position of the philosophy of consciousness.

Agreements and Differences between Berkeley and Hume
i) nominalism (agreement)

ii) the existence of the external world (matter) is not denied, but
it is construed as "unknowable." (This was succeeded by Kant.)
iii) the immediate sensation (=impression in Hume's term) does contain less than was contended previously
e.g., sight perceives only color and does not procure "distance" for example.

iv) the radicalization of the principles which underlie nature (e.g. causality)
the objective validity (necessity and universal validity) as well as the constancy and coherence of nature are denied. They only hold "psychological relevance."

v) The denial of the spiritual substance, in consequence, the notion of substance which is the basis of reality since Descartes' philosophy was thrown out of philosophy.

Agreements and Differences between Locke and Hume
i) the opposition between rational and empirical knowledge was radicalized by Hume.
a) the analytic proposition is called the proposition about relations of ideas
whose criterion of truth is the principle of contradiction
(all the mathematical knowledge)
which is radically distinguished from and opposed to
b) the synthetic proposition is called the proposition about matter of fact
whose criterion of truth is the principle of "verifying" it by experience

the synthetic versus the analytic is equated by Hume explicitly with the opposition the a prior versus the a posteriori

ii) all the relations of ideas which are not analytic but synthetic are not based upon the arbitrariness of our understanding, but
on the psychological law. Therefore, for example,
the relationship of a cause and an effect is now founded by Hume on the psychological law of association.

iii) ideas are classified as follows
reflections (internal ideas)
impressions (more forceful, more vivacious, more freshly given)
ideas (faded, older impressions)-difference only in degree
sensations (external ideas)
iv) Among ideas there are
simple ideas
complex ideas

Hume's Psychological Law of Association
1) Resemblance
ideas which resemble each other are associated
e.g., a picture‹its original object
2) Contiguity
ideas which are contiguous, i.e., close both in terms of "space" and "time,"
descriptive & experimental portion of moral and natura philosophy
3) Cause and Effect
ideas which are related to each other by causation
religion & metaphysics

the portion of physics and morality which are beyond experience

To Hume,
Epistemology is the discipline that aims at the establishment of the limits and degrees of validity (reliability) of sciences (and philosophy).

What is given in the immediate experience to Hume is far less in its content than Locke or Berkely even thought of. This is due to his understanding of the nature of consciousness.

The objects of our inquiry and research = the systems of ideas
i) mathematics ‹ its objects = relations of ideas
the truths are analytic = related to the possible, therefore
possesses a) intuitive certainty
b) demonstrative certainty
2) natural sciences 1 ‹ its objects = ideas of matter of fact
possesses a) the certainty of fact = that of sensation
3) natural sciences 2 ‹ its objects = ideas of matter of fact
possesses b) the certainty by inference (=causation) = probability

Causation (Hume does not talk about Causality)

Causation, the relationship between a cause and an effect, is not a priori
(not a rational judgment)
Causation is not analytic (not of the relation of ideas)

How does Hume understand the "necessary connection" between a cause and an effect?
1) This "necessary connection" is, according to Hume, is not necessary.
2) This "necessary connection" is an additional to the contents of those ideas (or impressions) given to us.
3) What we feel as "necessary" in causation is a psychological compulsion, which is based on and obtained by
i) repetition
ii) association
iii) habit

All the inferences by causation are beliefs and not knowledge (neither knowledge of fact, nor demonstrative knowledge)
Therefore, what is traditionally considered as knowledge is now divided into
i) knowledge
ii) belief
iii) faith (this is of lower grade than belief)

The existence of the external world is also this belief according to Hume!

Of Substance
According to Hume,
what is perceived by impression is not substance
(this no one disputes with)
it is a state of affairs and activities.

1) No Material Substance
it is not a product of our imagination,
it is a a product based upon our subjective habit
it is a name given to an aggregate of ideas
we objectify our subjective habit ‹ a material substance
It is an idea of "identity" (i.e., "resemblance") of the association of a set of ideas

2) No Spiritual Substance
There is no such a thing as the Spiritual Substance
Spirit or Soul is a name for the totality of our inner state, i.e., an aggregate of ideas which flow regularly in our consciousness.
Self or Ego cannot be perceived by reflection (internal knowledge)
what we call a spiritual substance or Mind or Self is a bunch of ideas in every second in a serious change, which would lead us to believe the existence of such a thing.

Since our Mind or Soul or consciousness lost is substantiality, the demand for "immateriality" or "immortality" also loses its meaning.

Hume's Positivism

1) Hume limits the scope of knowledge to i) mathematical truth
ii) factual truth of sense and experience (no inference)
This knowledge is extremely limited in the sense that
all the laws of nature, universal knowledge of nature are not included in here, but are classified as "beliefs" with high probability.
2) Hume was very skeptical as to the possibility of "inquiries" and its results in "natural" and "moral philosophy" which go beyond the limits of the ascertainment of "actually given in the sense."
‹ probable, customary ‹ practically useful "knowledge" (= beliefs in Hume's sense).

3) The Denial of Metaphysics
Knowledge (=beliefs) are needless to say going beyond the limit of all possible experience
The knowledge (-beliefs) based upon empirical inference dos not start with "empirical fact" and does not end in a conclusion which still remains within the boundary of possible experience
The scope of all possible experience = the scope of all possible knowledge

Inference of immortality of Soul
Inference of the existence of external world
Inference of the existence of God
all these are meaningless.

Philosophy of Religion
Hume's philosophy of religion is Deism and its radicalization.
i) the origin and the truths of religion = the objects of scientific (=phil.) inquiry
ii) observations of historical religions is the content of the above.

Moral Philosophy
Hume's moral philosophy is Hedonistic Determinism. Hume attempted to base the principles of morality empirically on passion and ultimately on pleasure and pain.

Human volition and action arise from mechanical effect of desire
desire ‹ passion
i) immediate passion
ii) mediated passion
are resulted from pleasure and pain.
Moral volition, moral judgment or moral virtue are produced by "regular" repetitive habit of passion
e.g., virtue is an agreeable feeling
vice is a disagreeable feeling

There is no Freedom of Will but Hume held Determinism
freedom is reducible to chance (no cause), which is untenable
the basis of determinism Hume saw not in ideas (as a cause), but in feeling.
We often talk about reason's overcoming our passion, but it is fallacious.
In reality, it is a matter of one passion to overcome another! What is normally called reason is no other than a quite passion which will lead us to a moral good.

What makes the moral distinction between good and evil is our feeling of pleasure and pain.

Moral praise and accusation about other actions are in essence the same as our aesthetic judgment of taste!
Political Philosophy (Omitted)