The Radical Notion of David Hume

The Radical Notion of David Hume

If Hume awakened Kant from his philosophical slumber, perhaps we should take a closer look at Hume’s thoughts.  Hume’s thoughts may be more radical than is commonly thought, and perhaps Kant’s response to Hume was a spectacular failure.

Furthermore, if we take Hume seriously, and if we take science seriously, we must figure out what we are to do.  Hume’s critique attacks and destroys a major assumption of science itself.  If there is no serious answer to Hume, then science has no philosophical foundations, if we assume that Empiricism is true.  Perhaps Empiricism is not true, after all.

Taking notes on Kasser’s lectures a little over a year ago, I wrote the following:

Dave Hume’s conclusions are more radical than Berkeley’s.  Hume takes empiricism to some of its logical conclusions.  Hume wanted to bring experimental methods to philosophy.  Applying this rigorously, Hume discovered that some of our crucial notions have a questionable link to experience.  Experience merely reveals one set of sensations followed by others.  These sequences of sensations do not reveal any causal link among themselves, and thus, our notion of causality (cause and effect) has no grounding in experience.  Our sense impressions are always changing, and thus, we do not experience anything enduring.  Even our sense of self does not endure.  Hume also speculated that we may not be thinking beings, but beings that experience one series of impressions followed by others. 

Can we call anything evidence that we do not experience now?  Can we be sure that our memory of experience and impressions is real, accurate or true?  This reasoning process ends in a deep form of skepticism.

Among Hume’s conclusions was that some of our core notions are meaningless or have no basis in experience, or mean something different from what we would think on first impression.  With this, Hume questioned philosophy’s position with regard to science.  Where does philosophy fit in with regard to scientific empiricism?  Hume also concluded with a notion of what is called “Hume’s Fork.” Hume’s Fork claims that meaningful statements must be in one of two forms:  (1) relations of ideas, or (2) matters of fact.  (1) can be things such as logic or mathematics, while (2) can be the empirical sciences.  Hume, as one would expect, was interested in matters of fact.  He saw his project as discovering the laws of the mind as Newton discovered laws of nature.  

This is a very shocking conclusion drawn from a major philosopher.  Perhaps Kant was justified in thinking for many years upon what Hume was getting at.  Kant, perhaps the greatest thinker of modern times, was fully aware of this devastating conclusion that Hume drew from strictly applying the philosophy of Empiricism.

After the aforementioned notes, I made the following comments:

In contrast to Hume’s conclusions questioning the legitimacy of philosophy, he demonstrates the exact opposite.  If one claims that empiricism justifies science, Hume’s reasoning demonstrates the potential illegitimacy of empiricism, not philosophy.  Philosophy investigates and then subsequently poses questions.  If these investigations reveal the lack of grounding in philosophy for empiricism, the philosophical critique holds.  To conclude that this line of reasoning undermines philosophy is backwards.  When a messenger (philosophy) delivers a message (empiricism has no rational ground), one is not credible in questioning the messenger (dogmatically holding to empiricism and assuming – not proving – that philosophy is the culprit).

This discussion contributes to a widely held notion among defenders of science that lack of evidence to any idea places the idea outside the bounds of knowledge.  Even empirical science has to abstract several stages from experience to reason toward physical laws and principles.  Furthermore, scientists will question the evidence itself when such evidence contradicts an established theory; this common practice is a spectacular contribution to the demonstration of the legitimacy of philosophy.  When one rejects evidence on theoretical grounds, one is doing philosophy.  Finally, the empiricist assertion cannot be taken seriously when one considers the entire realm of mathematics, where one can reason completely within a system of thought without any evidence whatsoever.  It would be foolish to claim that mathematics is not knowledge.

In conclusion, we know from observing scientific work that evidence of the senses – experience - contributes to science, but it is not clear how to connect evidence to theory.  This effort was a spectacular failure of the classical empiricists.  Their promise of a method to connect experience to theory, and thereby setting all other knowledge outside the bounds of knowledge, does not work.

So, does experience reveal one set of sensations followed by others?  It seems that Kant attempted to make the mind active in taking the input from the things in themselves, with the mind actively processing these things, thus accounting for cause and effect within things as they appear.  We can marvel at Kant’s spectacular efforts in his Critique of Pure Reason, but this gets us nowhere further from Hume.  Kant did not escape Hume’s trap that if we are Empiricists, one set of sensations follow another.  Who cares if the mind organizes and processes this information?  It still leaves us at square one. 

Hume’s devastating attack on Empiricism, I think, was a final blow.  The problem is that Kant followed him with a dazzling brilliance and ability for analysis, that, perhaps we forget Hume in the bright light of Kant.  It appears to me that Kant sidestepped this issue with a philosophical sleight-of-hand, as it were.  He does not address the core issue, but attempts to move cause and effect around to sooth us, but not give us an ultimate answer.

Let us make this very clear with an illustration.  You are performing measurements on the Second Law of Thermodynamics.  You have a thermometer.  You are taking a serious of measurements.  Every half hour, you look at the thermometer and record the temperature in your laboratory book.  If you believe in Empiricism, that we must base all our theories on experience, what connects one measurement to another measurement?  Between the first and second measurement, what happened?  You do not know, because you did not observe it.  You can only infer what happened.  Wait – but if you infer what happened, you are not relying on observation to tell you what happened between measurements.  If we cannot infer what happens between measurements, we cannot do science as Empiricists. 

We cannot say, under any circumstances, that we rely only on evidence for our knowledge and theories. 

So, what are we to say?

Freddy Martini