On Cause & Effect I

Hume was a philosopher who questioned humans everday use of rationality. His axiom was..."We learn cause and effect from everyday experience." He asked..."Where does it state that a particular cause and effect will always occur in the same fashion... every single time?"

Hume’s point was that the only thing we learn from experience is the succession of events in time rather than the causal connection between them.

There is really nothing wrong in his argument. The conclusion is that... We acquire knowledge from experience alone.

…To this day we still say that there is regularity in our experience.
Hume’s point of view was that... we should say that there have been regularities rather than... there is.... Consequently, we cannot know whether the regularity in question will continue.

This is roughly what Hume suggests: We cannot know anything about regularities but we are unfortunatedly inclined by our nature, to believe them.

…From an evolutionary perspective we are programmed to see causal connections and reasons... even though they do not exist. According to Hume, we continue with this because it helps us to live…
Hume could not have known the unformulated evolutionary theory, but his naturalist view was close to that.

On the Definition of Ideas and Impressions

The contents of the mind: (1) ideas (2) impressions (sensations & feelings) -- Ideas (concepts, beliefs, memories, mental images, etc.) are faint & unclear; impressions are strong & vivid.
Ideas are derived from impressions: All ideas are copies of impressions.
The meaning of ideas depends on impressions.

Hume’s Epistemology

“Impressions” and “Ideas”:

•Question: Where do our “ideas” come from?
Answer: From various “impressions.” An “impression” is what you have when you are actually experiencing something. When you are eating the apple, you have an impression of its juiciness and tartness. When (later) you remember eating the apple, you have an idea of its juiciness and tartness. Impressions are more vivid .

•The impression lasts only as long as the experience lasts; the idea is “filed away” in your memory.
•Any idea not derived from an impression is bogus!

Hume’s Epistemology - Association of Ideas:

•When we have an experience of something (seeing and then eating an apple) we have collections of impressions of (round, red, juicy, etc.). What leads our minds to form the complex idea of an apple?

•Hume’s answer: through repeated experiences we come to associate these ideas with each other.There are three “Principles of Association”:

Association of Ideas:Three “Principles of Association”:

1.Resemblance. Our minds bring similar ideas together.

2.Contiguity. Ideas connected in space & time are viewed by our minds as having to belong together.

3.Cause. When one event regularly follows another our minds tend to ascribe a causal connection between them.

Association of Ideas (continued):

As we will see: Hume insists that we have no reason to believe that there is an objective basis for these associations. Just because our minds “associate” certain ideas together, this does not mean that these ideas “objectively” belong together!
Objective: Of or having to do with a material object. Having actual existence or reality. Something that actually exists.

Association of Ideas (continued)

We are not entitled to draw any conclusions about the way things are “outside” of our mind based on observations about how the mind processes its ideas. The workings of our mind tell us nothing about the way reality is.
This insistence marks Hume’s position as a form of “skepticism” about any reality “outside” the mind.

On Two Kinds of Ideas or Judgments

All the objects of human reason or inquiry may naturally be divided into two kinds: relations of ideas and matters of fact:

1. Judgments concerning relations of ideas

2. Judgments concerning matters of fact

This is known as Hume's Fork

Judgments Concerning Relations of Ideas

Ø Intuitively or demonstrably certain
Ø Discoverable by thought alone [a priori]
Ø Cannot be denied without contradiction

“Relations of Ideas” and “Matters of Fact”:

•Some ideas are logically connected: for example: “bachelor” to “unmarried,” “puppy” to “dog,” “4” to “2x2”: All bachelors are unmarried; all puppies are dogs; 2x2= (always) 4.
•In the above cases (and others like them) we have “necessary truths.” The above statements cannot be false. Such statements Hume calls “Relations of Ideas.”

“Relations of Ideas” and “Matters of Fact”:

•Other ideas are not logically connected: for example: “bachelor” to “bald,” “puppy” to “playful,” “four” to “the number of children Jones has”: Some bachelors are bald; some puppies are not playful; Jones has four children.
•In the above cases (and others like them) the statements may or may not be true. Even if they are true, they could have been false. Hume calls such statements “Matters of Fact.”
•[This distinction corresponds (roughly) to the distinction between “necessary” and “contingent” truths.]

Why does Hume emphasize this distinction?

1.To underscore the limits of what Reason can know: All that Reason can do is assent to logical or mathematical truths. Reason can tell us nothing about “matters of fact,” i.e., about what the world is really like.
2.Hume says that anything we think we do know about the world, can only be based on experience. We can have no knowledge of what the world is like... apart from experience.
3.But then again: that “knowledge of the world” is derived from our impressions. We have no knowledge of anything beyond our impressions/ideas!

Judgments Concerning Matters of Fact

*Every judgment concerning matters of fact can be denied without contradiction (e.g., "the sun will not rise tomorrow").
*Neither intuitively nor demonstrably certain
*Not discoverable by thought alone [a priori], but rather on the basis of sense experience [a posteriori]

“A priori” and “A posteriori” knowledge:

Hume insists:
1.Only a posteriori knowledge is knowledge about reality: the facts of the world—the way the world is.
2.A priori is knowledge only of definitions, logic or mathematics, not of how the world is.

Any knowledge of truths that are universally true is not knowledge of reality!

“A priori” and “A posteriori” knowledge:

Aren’t both of the following universal truths?
1.“The angles in a triangle add up to 180º.”
2.“Water boils at 212º Fahrenheit at sea level.”

Hume:
The first is a universal truth, but does not express knowledge of reality.The second is not known to be a universal truth. For all we know it could be proved false.

“A priori” and “A posteriori” knowledge:

Question: Would Hume agree with Descartes that we can construct a complete system of knowledge of reality based upon universal truths that are innately known (a priori) by the mind?

Answer: No way! Any knowledge of reality is constructed from particular observations. The generalizations we make, based on those observations, could always turn out to be false!

Consequences of Hume’s Epistemology:

Famous Quote:
“If we take in hand any volume … let us ask, “Does it contain any [logical or mathematical reasoning]? No. Does it contain any [experience-based] reasoning concerning matters of fact and existence? No. Commit it then to the flames, for it can contain nothing but sophistry and illusion!”—Hume

Hume on “Causality” (continued):

Event 1: Billiard ball A hits Billiard ball B.
Event 2: Billiard ball B begins to roll away from its spot.
I assume that Event 1 is the “cause” of Event 2. But what do I actually observe?
Hume says: All you observe is that
(a)Event 1 is spatially adjacent to Event 2: they are contiguous;
(b)Event 1 is prior in time to Event 2; and
(c)Events 1 and 2 are constantly conjoined: every time you see one ball hit another, the second one moves.

Thus, you observe three things: (a) contiguity, (b) temporal priority, and (c) constant conjunction.

•When we think of Event 1 causing Event 2, however, we think of something stronger than these three: we think that there is a “necessary connection” between the events:
•We think: If ball A hits ball B, then there’s no way that B won’t move! B’s motion is inevitable, or made “necessary” by A’s impact on it.

•Hume’s challenge: Show me the “necessity”! You observe the two events, you notice their contiguity, priority and constant conjunction, but then you (illegitimately) “impose” the necessity!

•Hume’s challenge (continued): How can you be sure that the next time A hits B, B will move?
•Your reply: There is a “Law of Nature” (one of Newton’s laws of motion) that dictates that whenever A hits B, B will move. So I can predict with certainty that B will move when A hits it the next time.

•Hume’s reply to you: What is your knowledge of this “law” based on?
•You to Hume: On uniform past experience. In the past B has always moved when hit by A. What has been true in the past will continue to be true in the future.

•Hume to you: What makes you think that just because something has always happened in the past, it will continue to happen in the future? What “guarantee” is there that “the future must resemble the past”?
•You: Because in the past “the future has always resembled the past.”

•Hume: Gotcha! You’re arguing in a circle! You are relying on the assumption that the future will resemble the past in order to support the assumption that the future will resemble the past. That’s “begging the question!”

On Cause & Effect II

And why do we believe that there is a "tie or connection" between cause & effect?

Because the belief arises entirely from experience [a posteriori, not a priori], namely, the experience of finding that two events (cause & effect) are "constantly conjoined" with each other.

Even though the perception is based on experience, It is not logically necessary that a particular effect follows a particular cause; it is just a fact of experience.

Hume on the “Principle of the Uniformity of Nature” (continued)

We expect nature to be uniform: We believe that patterns of regularity observed in the past will continue to hold into the future. This is called our belief in the “Principle of the Uniformity of Nature” (PUN).

PUN is essential to science. The “Laws of Nature,” we believe, will continue to hold in the future as they have held in the past. Without this belief, science is not valid

•Hume’s Critique: Belief in PUN is an irrational belief. The truth of PUN is not established by logical reasoning (Relations of Ideas), and it cannot be established as an observed fact (Matters of Fact) without circularity!

We have no logical reason to believe that the future will continue to resemble the past.

The Nature & Limits of Inductive Reasoning

The problem of induction:
*Induction is the process of drawing inferences from past experiences of cause & effect sequences... and projecting one's expectations to present or future events.
*Hume's point is that an "effect" cannot be validly deduced from its "cause"
*The inference from "cause" to "effect" is based on past experiences of "constant conjunction," and these past experiences . . . .accustom or habituate us to believe that one event is the cause of another, which we believe to be the effect of the prior event.
This is what leads us to believe that . . . .the future will always resemble the past. It is all a matter of CUSTOM or HABIT.
This is the foundation of . . . .

The Idea that there is a Necessary Connection between Cause & Effect

If this is a meaningful and true idea, then (according to Hume) it must be derived from our sense impressions.
What, then, is the sense impression from which this idea is derived?
There is no sense impression of causal power or necessary connection of cause & effect, but we do experience the following. . . .
v(1) The spatial contiguity,
v(2) The temporal succession, and
v(3) The constant conjunction
........of "cause" & "effect."

It is From This Experience:

ØEspecially the experience of constant conjunction, that the idea of a necessary connection between "cause" & "effect" arises (or is inferred);
ØBut the "inference" is simply a matter of "custom or habit."
ØThis seems to mean that the "inference" here is psycho-logical rather than logical. Actually, there is no experience of the necessary connection between cause and effect. Thus, all factual judgments (which are based on the assumption that there is a necessary connection between cause and effect) are subject to doubt.
ØNo necessity, no certainty.

The Value & Limitations of Skepticism

Hume discusses 5 kinds of skepticism:
(1) "Antecedent" skepticism

(2) "Consequent" skepticism

(3) Skepticism concerning mathematical reasoning

(4) Extreme skepticism concerning matters of fact

(5) Moderate skepticism

What about Mechanical Causation

Malebranche and Hume went on to deny the intelligibility even of mechanical causation:
Suppose we see a yellow billiard ball moving towards a red one and colliding with it. Why do we expect the red one to move?

Hume’s Thought Experiment (E 4.6)

Imagine Adam, newly created by God, trying to envisage what would happen:
He's never seen a ball in his life or for that matter seen two balls collide, and now we expect him to know what's going to happen?
** how could he possibly make any prediction at all in advance of experience?

** Just because we know in advance what will happen does not mean that Adam will know in advance of experience.

“Intelligibility” and Experience

The “intelligibility” of mechanical causation seems to be an illusion, based on familiarity.
When we have repeated experience, our expectation comes so naturally that we imagine we could have known – even the first time – what would happen.
That’s wrong: only experience can tell us what causes what. A priori, we have no understanding even of mechanical impact!

Hume on Science – Negative

In advance of experience, we cannot know anything about what causes what.
*So experience is our only basis for making predictions about the unobserved.
All inference from experience is based on the assumption that we can extrapolate from observed to unobserved (“induction”).
*But this assumption has no rational foundation whatever! The basis of our reason is animal instinct rather than angelic insight.

Hume on Science – Positive

The Foundation of Inductive Reasoning
*Scientific (like all empirical) reasoning is founded not on insight, but on a brute assumption that the future will resemble the past, for which no solid basis can be given.

Good and Bad Reasoning
*But this doesn’t mean that all inductive reasoning is equally good (or bad). The wise thing to do is to reason consistently with this irresistible brute assumption.

Example of Bad Reasoning - Miracles

Why would I Believe a Miracle Report?
*Because I have experience that reports of witnesses tend to be true. My belief is based on inductive extrapolation.

Why Shouldn’t I Believe a Miracle Report?
*Typically, the inductive evidence against any miracle will be far stronger than the inductive evidence in favour. I have lots of experience of people being mistaken, misled, tricked …

Enter Immanuel Kant

Hume has to be wrong, because we have clear examples of “synthetic a priori” knowledge:
truths about the world knowable independently of experience, that we see had to be that way:
–Metaphysical principles (e.g. universal causation)
–Euclidean geometry (e.g. Pythagoras’ theorem)
–Newtonian mechanics (e.g. conservation of momentum).

Hume’s Triumph!

Einstein’s General Relativity (1915)
–Space is gravitationally “curved”
–So Euclid’s axioms probably aren’t true, and they’re certainly not knowable a priori.

Quantum Mechanics (1925)
–Fundamental particles don’t work at all as we (or Newton) would have expected: their behaviour is describable, but not “intelligible”.
–Randomness seems to be ubiquitous (though this would surprise both Hume and Kant!).

Hume’s Views on Religion

•Hume was raised in an orthodox Calvinist family. He abandoned his religious beliefs early in life, and retained an interest in religion only as an “outsider.”
•Hume argues that all the traditional arguments for the existence of God (ontological, cosmological, teleological, etc.) are failures, and he rejects the notion of a “Natural Theology.”
•(Reminder: Aquinas believed that Reason, apart from Revelation, could by itself establish some truths about God: God’s existence, and many of God’s essential attributes. Such efforts were traditionally called “Natural Theology.”)

Critique of the traditional arguments for the existence of God:

Hume’s critique of the traditional arguments for the existence of God and his attack on Natural Theology in general are developed in his posthumously published: "Dialogues Concerning Natural Religion."

Hume’s Views on Religion II

Hume argues that all the traditional arguments for the existence of God (ontological, cosmological, teleological, etc.) are failures, and he rejects the notion of a “Natural Theology.”
(Reminder: Aquinas believed that Reason, apart from Revelation, could by itself establish some truths about God: God’s existence, and many of God’s essential attributes. Such efforts were traditionally called “Natural Theology.”)

In addition, Hume argues forcefully that the existence of evil is a powerful objection to the existence of an all-powerful, all-knowing and perfectly good God.

It is important to realize that Hume does not take himself as having proved that God does not exist: Showing that proofs for a particular conclusion fail to establish its truth is not the same as showing that the conclusion is false!

Hume claimed that “by destroying Reason (i.e., rational arguments supporting belief in God), I have made room for Faith.” Hume did not object to people’s religion being based on faith, as long as they did not try to “justify” their faith by basing it on rational arguments!

The Irrationality of Believing in Miracles: David Hume

Hume’s Thesis: It is never reasonable to believe second hand reports concerning miracles.

Reasons for Not Trusting Testimonies

•The opposition of contrary testimony: when witnesses contradict each other
•The character or number of the witnesses: too few or of a doubtful character
•The manner of delivering the testimony: when delivered with bias, hesitation, violent declaration

Definition of a Miracle

•General definition: "a miracle is a violation of the laws of nature"
•More accurate definition: "a transgression of a law of nature by a particular volition of the deity, or by the interposition of some invisible agent"

Main argument against miracles

•The evidence from experience in support of a law of nature is extremely strong.
•A miracle is a violation of a law of nature.
•Therefore, the evidence from experience against the occurrence of a miracle is extremely strong.

Four additional arguments against miracles

•Witnesses lack Integrity
•Predisposition to Sensationalize
•Abound in Barbarous Nations
•Miracles Support Rival Religious Systems

Closing quotation

•"And whoever is moved by faith to assent to it [i.e. belief in the Biblical miracles], is conscious of a continued miracle in his own person which subverts all the principles of his understanding and gives him a determination to believe what is most contrary to custom."

Two Interpretations of Closing Quote

•Friendly interpretation: the miracles and prophecies in the Bible are not rational, and can only be believed through an act of divinely inspired faith
•Unfriendly interpretation: belief in miracles is so irrational that it requires miraculous stupidity on the part of the believer