# Problem Solving > ###### Central Idea > What justifies the knowledge we gain? Popper's [Problem Driven Epistemology](Problem%20Driven%20Epistemology.md); the [Problem Solving Process](Problem%20Solving%20Process.md). We are continually drawing [Ever Grander Conclusions from Ever Scantier Evidence](Ever%20Grander%20Conclusions%20from%20Ever%20Scantier%20Evidence.md). Even though [we do not accord equal significance to all sensory impressions](We%20do%20not%20accord%20equal%20significance%20to%20all%20sensory%20impressions.md), there is no avoiding the fact that when we weigh up this ever scantier evidence, we are literally contemplating nothing more than *patterns of weak electric current trickling through our own brains*. So what [justifies](Justification.md) the inferences we draw from these patterns? It is certainly not a matter of logical [Deduction](Deduction.md). There is no way of proving from these or from any other observations that the external universe, or multiverse, exists at all, let alone that the electric currents received by our brains stand in any particular relationship to it. Anything or everything that we perceive might be an illusion or a dream. [Solipsism](Solipsism.md) cannot be logically disproved. Since solipsism is logically consistent with your perceiving any possible observational evidence, it follows that *you can logically deduce nothing about reality from observational evidence*. How, then, is it possible to say that [Eddingtons Eclipse Observations](Eddingtons%20Eclipse%20Observations.md) rule out the Newtonian world view? If 'ruling out' does not mean 'disproving', what does it mean? Why should we feel compelled to change out world view, or indeed any opinion at all, on account of something being 'ruled out' in that sense? This critique seems to cast doubt on the whole of science — on any reasoning about external reality that appeals to observational evidence. If scientific reasoning does not amount to sequences of logical deductions from the evidence, what does it amount to? Why should we accept its conclusions? This is known as the [Problem of Induction](Problem%20of%20Induction.md). For most of science, it was believed that science worked via [Induction](Induction.md). But this is false - [Science Does Not Work Via Induction](Science%20Does%20Not%20Work%20Via%20Induction.md). It has three flaws that illustrate this most clearly: 1. Flaw 1 - [Prediction is not Explanation](Prediction%20is%20not%20Explanation.md): Generalized Prediction is _not_ tantamount to a new Theory 2. Flaw 2 - [Russells Chicken](Russells%20Chicken.md): Even mere _predictions_ cannot be justified by observations 3. Flaw 3 [Induction is Impossible](Induction%20is%20Impossible.md): Inductive Extrapolation to Form New Theories is _not_ Possible. [All Observations are Theory Laden](All%20Observations%20are%20Theory%20Laden.md), [they are *not* Sources of Knowledge](Observations%20are%20not%20Sources%20of%20Knowledge.md) If we want to understand the true nature of knowledge we must accept the fact that inductivism is false, root and branch. No scientific reasoning, and indeed no successful reasoning of any kind, has ever fitted the inductivist description. What, then, is the pattern of scientific reasoning and discovery? What we need is an explanation-centered theory of knowledge: a theory of how explanations come into being and how they are [justified](Justification.md); a theory of how, why and when we should allow our perceptions to change our world-view. The prevailing theory of scientific knowledge, pioneered by Karl Popper, provides just that. It can be regarded as a *theory of explanations*. It states that [Science is Problem Solving](Science%20is%20Problem%20Solving.md) and we will call it [Problem Driven Epistemology](Problem%20Driven%20Epistemology.md). Problem solving begins with our best existing theories. When some of those theories seem inadequate to us, and we want new ones, that is what constitutes a [Problem](Problem.md). The problem may be that the existing explanation seems too glib, or too awkward. It may seem unnecessarily narrow, or unrealistically ambitious. One may glimpse a possible unification with other ideas. Or a satisfactory explanation in one field may appear to be irreconcilable with an equally satisfactory explanation in another. Or, it *may* be that there have been some surprising observations - such as the wandering of the planets, or some plot in a data science context - which existing theories did not predict and cannot explain. Now this last type of problem may appear at first glance to resemble to inductivist paradigm. But we can see that is only superficially so. An unexpected observation never initiates a scientific discovery unless the preexisting theories already contain the seeds of the problem ([All Observations are Theory Laden](All%20Observations%20are%20Theory%20Laden.md), as described in [Poppers Theory of Knowledge](Poppers%20Theory%20of%20Knowledge.md)). This is why for millennia humans chose to try come up with [better explanations for *planets* and not *clouds*](Science%20is%20driven%20forward%20by%20problems,%20not%20observations.md). One solves a problem by following the [Problem Solving Process](Problem%20Solving%20Process.md). [Science follows this exact problem solving process](Science%20is%20Problem%20Solving.md), with the additional constraint that it always includes a particular method of rational criticism: *experimental testing*. We can compare [inductivism](Induction.md) and [problem solving](Science%20is%20Problem%20Solving.md) as follows: * Inductivism is *observation* and *prediction* based. In reality science is *problem* and *explanation* based. * Inductivism supposes that theories extracted from observations, or are justified by them. In reality, theories begin as unjustified conjectures in someone’s mind, which typically precede the observations that rule out rival theories. * Inductivism attempts to justify predictions as likely to hold in the future. Problem solving justifies an explanation as being better than other explanations available in the present. * Inductivism is a dangerous and recurring source of many sorts of error, because it is superficially so plausible. But, again, [inductivism is false](Induction%20is%20Impossible.md). When we have [solved a problem](Problem%20Solving%20Process.md), we are left with a new set of problems, which are preferable to the old ones. This theory that knowledge can only grow by conjecture and refutation is known as [Evolutionary Epistemology](Evolutionary%20Epistemology.md). [Evolutionary success in both science and biological evolution depends on the creation of objective knowledge](Evolutionary%20Success%20Depends%20on%20the%20Creation%20of%20Objective%20Knowledge.md). --- Date: 20241201 Links to: Tags: References: * []()