Is persistent uncertainty irrational?

Question

Doubt, uncertainty, and questioning things are considered hallmarks in philosophy. Not being certain in a belief is considered a virtue due to how often we are mistaken.

But philosophy is also associated with finding out the truth about things. However, being uncertain implies having a probabilistic form of belief that doesn’t seem to exist in reality for many things. For example, ghosts are either real or not. The earth is either a sphere or not. With these kinds of things, reality is binary. When it comes to matters of existence, there are no grey areas. As such, why is it sensible to leave even a bit of a doubt in your beliefs about these matters?

If a rational belief is one that amounts to having a belief that is both justified and is true, how can it be rational to even say “I think the earth is most likely a sphere but I could be wrong.”

If the earth is a sphere, then wouldn’t you ultimately be wrong for even thinking that it’s a possibility that the earth isn’t a sphere? If it’s not a sphere, you would also be wrong.

Being uncertain seems to make your belief wrong either way. Being certain atleast seems to make your belief correct if you turn out to be right. Why is the former then considered more rational?

Answer 1

The short answer is: No. Scientific Method considers all truths discovered to be tentative, and only as certain as their evidence - meaning there is no space in science for total certainty about anything, we just don't have evidence of ghosts plus reasons to relate them to cognitive biases, and psychology like guilt or lack of closure. And science is considered a rational mode of investigation.

Proof in mathematics can demonstrate a consequence with certainty - but, only once definitions, axioms and abstractions are accepted as certain.

Hume identified the Problem of Induction: however reliable the past has been as a guide, the universe has the last word on future regularities or lack if them.

You might like this answer on how we can reconcile mathematical universality, with the lack of certainties in science: The Unreasonable Ineffectiveness of Mathematics in most sciences

there are no grey areas

What about actual areas, where everything is grey? And, granted it's metaphorical sense, what about challenges to the law-of-the-excluded-middle? For instance in the Buddhist 'four cornered' logic of the catuskoti, it can be recognised that multiple layers of thinking about things can be valid, yet give incompatible or irreconcilable results. See eg: The logic of Buddhist philosophy goes beyond simple truth.

Humility about our knowledge, and recognising what basis we have drawn our conclusions from is part of the conclusiins, has been crucial to moving away from endless religious and ideological wars. Other than math, only religious zealotry imbues people with a sense of certainty, and no I don't think that is better than recognising you have been or could be wrong.

Being wrong is part of the learning process, fear of being wrong inhibits learning, and creativity.

Answer 2

The problem is that the justification is not often infallible, for example, in the case of justifying why earth is a sphere, empirical evidence is used. However even the empirical evidence can be questioned, like what if the earth is some other shape, and we are being deceived somehow, or other alternate possible explanations of what else might be happening.

Thus, keeping doubt in such claims is more rational because you acknowledge that you don't have an infallible justification, and that your claims could change based on new information/evidence, and also that giving an infallible justification is not possible. Although the earth might actually be a sphere, but we cannot be certain that it is, due to the same reasons as before. Without doubt, you are just saying that your justification is enough and infallible, which isn't true or rational.

Also, the statement "I think the earth is most likely a sphere but I could be wrong." is equivalent to saying "I think the earth is a sphere or I might be wrong", the below truth table makes it clear enough then on what is more rational.

Answer 3

In the tradition of western Philosophy, this goes back to the Socratic paradox "I know that I know nothing" as recounted by Plato. Given human ability to perceive reality (including perception of their own limits) precisely, it is rational to remain doubtful.

If the earth is a sphere, then wouldn’t you ultimately be wrong for even thinking that it’s a possibility that the earth isn’t a sphere?

It depends. There is a difference between reasonable doubt and unreasonable doubt, which is driven by the knowledge you have and the alternative you conceive, and what is at stake.

As a person who never went to school and never travelled, a belief that earth may rather be a small disc is not unreasonable, even if wrong.

Answer 4

There is something to be said for being aware of the limits of rationalisation. Both Buddha and Kant have a similar line in this. Buddha with the undeclared or indeterminate (avyākata) questions.

Avyākṛta : Ten indeterminate questions e.g. Cula-Malunkyovada Sutta

'The cosmos is eternal,' ... 'The cosmos is not eternal,' ... are undeclared by me. And why are they undeclared by me? Because they are not connected with the goal... They do not lead to disenchantment, dispassion, cessation, calming, direct knowledge, self-awakening, Unbinding.

And Kant's mathematical antinomies : of space and time.

• Thesis: The world has a beginning in time, and is also limited as regards space.
• Anti-thesis: The world has no beginning, and no limits in space; it is infinite as regards both time and space.

of which the SEP says in 4.1 The Mathematical Antinomies

In each of these antinomial conflicts, reason finds itself at an impasse. Satisfying the demands placed by our rational capacity to think beyond experience, the thesis arguments offer what appears to be a satisfying resting-place for explanation. ... In each of these cases, the conflicts are resolved by demonstrating that the conclusions drawn on both sides are false.

How does Kant demonstrate this? ... for example, we may want to know, as in the first antinomy, whether the world is finite or infinite. We can seek to show that it is finite by demonstrating the impossibility of its infinitude. Alternatively, we may demonstrate the infinitude of the world by showing that it is impossible that it is finite. This is exactly what the thesis and antithesis arguments purport to do, respectively.

Kant goes on to establish limits to rationalisation in his Critique of Pure Reason. So a couple of precedents there for living with uncertainty.