human life is based on suspicion and assumption, rather than certainty?

Question

A murder occurred, so the police came to the house where the crime took place, and as soon as they entered, they found a person whose clothes were stained with blood and carrying a knife in his hand. When they began the investigation, they discovered that this person had disagreements with the victim.

No rational person will doubt that these three pieces of evidence: the blood-stained clothes, his possession of the knife, and the disagreements with the victim, represent clear evidence that this person is the killer.

But let us think a little. Is there a possibility, even 1%, that this accused is innocent? Is it logically impossible that the real killer epilepticized this accused and then killed his victim and stained the accused’s clothes with blood to make it appear as if he was the killer, and that his holding of the knife was accidental, as if he only wanted to inspect it at the moment the police entered, and that his differences with the victim were not enough to push him? to commit the crime.

All of this is possible, there is no impossibility in it, but nevertheless The judge will never consider these possibilities and will rule that the evidence is valid and that it is sufficient to prove the crime against the accused.

Can this show that people’s actions in this world are based on suspicion/assumption, not certainty? Rather, there is no hope of achieving certainty in most of the events of the world, and that is okay.

The pride in acting on the information of a single person, since it indicates suspicion, not certainty.

Is certainty an Impossibility that we can't achieve rather we base our perception of reality based on our suspicion and assumptions?

Answer 1

More than 2.500 years ago the Greek philosopher Xenophanes expresses a similar view (Translation due to K. Popper):

But as for certain truth, no man has known it,
    Nor will he know it; neither of the gods,
Nor yet of all the things of which I speak.
    And even if by chance he were to utter.
The perfect truth, he would himself not know it:
    For all is but a woven web of guesses.

These lines can be taken as an entry point to the theory of cognition due to the modern philosopher Karl Popper.

There is not only a destructive viewpoint, but Popper develops the positive insight of his theory of falsification, see Karl Popper: In Search of a Better World, the lecture "Toleration and intellectual responsibility".

Answer 2

I think the problem is deeper and it is a problem not fully fleshed out in the history of philosophy apart from a few.

In your case, it is of course true that one cannot be certain of the fact that the accused is the murderer. But framing it in this way implies that one has a certain degree, a certain confidence, a certain conviction in a belief that can be represented as a probability.

But with closer inspection, this idea of belief just simply doesn’t amount to reality and arguably, it can be considered meaningless. Try as you might, you can never actually justify any figure to any belief! What probabilistic figure would you attach to the belief that the accused is a murderer? 99%? If so, why not 98? Or 99.5? Are you not sure about the exact figure and would rather say that it just be within a range like 90-99%? If so, why not 89-99%? Or 88-98%? How sure are you that it should be 99% for example? Is this level of surety also supposed to be put in the form of a number? Wouldn’t this lead to an infinite regress?

To me, attaching a level of confidence to a belief seems meaningless, and anything that dissappears upon closer inspection should be simply thrown out. In reality, you only ever believe something in comparison to another belief. In this case, the comparison is with the belief that the accused is innocent.

So, you can simply ask yourself: what would you bet on? the accused being innocent or the accused being guilty? No talks of numbers, figures, convictions, or probabilities are needed here. You simply choose how you would act and never have to worry about how certain you are of anything!