Will the sun rise tomorrow? (Venue: by the river)

(Scroll down for topic intro)

THE VENUE: By the river

The weather forecast is hot and sunny, so let's do some philosophy by the river for the first time this year. I have updated the location below and removed the attendee limit.

When we meet indoors, we run the same event in two locations: Caffè Nero and Starbucks, so as to provide capacity for as many people who would like to attend, without overwhelming any one venue. Thus, there will be two events published, and you can choose which one to attend. Please don't sign up for both. This event is for the Starbucks location.

We meet upstairs at Starbucks. An organiser will be present from 10.45. We are not charged for use of the space so it would be good if everyone bought at least one drink.

An attendee limit has been set so as not to overwhelm the venue.

Etiquette
Our discussions are friendly and open. We are a discussion group, not a for-and-against debating society. But it helps if we try to stay on topic. And we should not talk over others, interrupt them, or try to dominate the conversation.

There is often a waiting list for places, so please cancel your attendance as soon as possible if you subsequently find you can't come.

WhatsApp groups
We have two WhatsApp groups. One is to notify events, including extra events such as meeting for a meal or a drink during the week which we don't normally put on the Meetup site. The other is for open discussion of whatever topics occur to people. If you would like to join either or both groups, please send a note of the phone number you would like to use to Richard Baron on: website.audible238@passmail.net. (This is an alias that can be discarded if it attracts spam, hence the odd words.)

THE TOPIC: Will the sun rise tomorrow?

This week's topic has been prepared by Duncan.

You might think that it definitely will. After all, it has risen every other morning, so why shouldn’t it rise tomorrow ? You’ve probably arranged your life accordingly and made plans and commitments. But can you be sure ?

And presuming the sun does rise tomorrow morning, will you eat your breakfast because you "know" it will nourish you, or just because it has worked in the past ?

We often operate on the basis of inductive reasoning, where we observe specific examples or data points and identify underlying patterns to form broad, forward-looking generalisations or theories. But because these conclusions are based on probability rather than absolute certainty, they are inherently open to revision as new evidence emerges. If the sun didn’t rise tomorrow morning, you might revise your predictions about future mornings.

Inductive reasoning proceeds from the specific to the general case, whereas deductive reasoning moves in the opposite direction.

We might appeal to the uniformity of nature, but that is itself based on prior observations. We cannot prove deductively that the sun will rise as expected because it is not a logical contradiction to imagine nature changing tomorrow. And we can’t prove it inductively because attempting to justify induction using past successes assumes induction works in the first place (which would be circular reasoning).

Enlightenment thinkers prized science and causality (e.g., Isaac Newton's physics), assuming they were products of pure mathematical and logical reason. David Hume argued otherwise. He claimed we never actually observe causes or "necessary connection"; we only experience "constant conjunction" (Event A happening, followed by Event B; fire, then heat). Our belief that the future will resemble the past is a habit of the mind, not a demonstrable truth of reason.

Hume devises a strategy to prove his skeptical conclusion. He asks us to imagine that we could prove the principle that the future will resemble the past. How would we construct such a proof?

Well, as Hume tells us, a proof needs a plausible argument, and there are two kinds of plausible arguments: deductive arguments (which are certain) and inductive ones (which are only probable and depend on the amount of evidence gathered). So, we would need to prove with either certainty or probability that the future will resemble the past. Then we can be confident (at least to the extent of the probability) that the sun will rise tomorrow, and a whole host of other predictions about the future based on past experiences.

So first, can we prove the principle with an argument that is certain (deductive)?

Hume provides a plausible argument that we cannot. First, he says all knowledge comes to us through our senses. We shall only count as evidence that which someone can see, smell, touch, taste, or hear. Second, he says The Future Will Resemble The Past Principle is a universal principle, meaning that it asserts that the future will always resemble the past. Third, it is impossible to empirically prove any universal, as to do so would require observing all possible instances of its application. So we would need to have the sum total of all possible experiences as evidence to prove that the future will always resemble the past. For instance, we would need to know about all future sunrises, which is impossible. To have this kind of knowledge would necessitate that we live forever; and even then, we would not have experienced the mornings before we were born. Thus Hume concludes that we cannot have definitive proof (that is, certainty) of the principle.

Can we prove the principle with an argument that is probable (inductive), then? Again Hume provides a compelling argument that we cannot.

The proposal is now that we can have an inductive argument for our The Future Will Resemble The Past Principle. However, this is a logical fallacy, since in order to operate, all inductive arguments must presume the future resembles the past. In inductive arguments, the arguer makes observations, and infers general rules or conclusions using the idea that future observations will be like the past observations. So, if we attempt to justify the principle that the future will resemble the past by an inductive argument – by for instance saying it has done so on previous occasions, so it will do so again – then we would be effectively proving the principle by assuming it, what is committing the fallacy of circular reasoning. We can indeed summarise the problem by saying that in order to prove induction through an inductive argument, we need to first assume the validity of inductive argument. In this kind of argument, nothing is proven, for the conclusion is presumed in the argument. Hume concludes therefore that we cannot justify the principle of induction with an inductive argument.

So the conclusion is that the essential inductive (and therefore scientific) principle that the future will resemble the past cannot be proven. No certain (deductive) or probable (inductive) arguments can justify the Future Will Resemble The Past Principle. So we cannot reasonably hold that the sun will rise in the morning even with probability, because this assumes the Future Will Resemble The Past Principle, which Hume has shown cannot be proven.
For Hume, then, we do not know that the sun will rise tomorrow, but we have a strong inclination to believe that it will, and we ought to act on that. Our feelings, for Hume, are sufficient for practical action.

If we ran our lives on purely inductive principles, we might be surprised when things don’t go as expected. As the old joke goes: "When someone dies, it's never me.”

Hume's own "skeptical solution" was to invoke custom and habit. Rationally, our belief in induction is a survival instinct rather than an airtight logical proof.

Questions:

Does science rely on faith? Since science uses inductive reasoning to build laws, are our most rigorous scientific theories ultimately built on an unprovable assumption? Or are there some fundamental laws that are beyond question?

Are probabilistic solutions valid? (e.g. using the law of large numbers or Bayesian probability). Do these solve the problem, or just quantify our uncertainty?

What about Karl Popper's theory of falsification ? He argued we can never prove a theory true via induction, but we can definitively disprove it. Does this sidestep the problem?

Whilst we can’t be certain that week's event will take place, we haven’t missed a Sunday in several years, so there's a 99.999% (approx) chance that it will.

Further reading:
https://philosophynow.org/issues/160/Humes_Problem_of_Induction