Evidence
In phenomenology, evidence is limited to intuitive knowledge, often associated with the controversial assumption that it provides indubitable access to truth.
In the philosophy of science, evidence is material that confirms or disconfirms scientific hypotheses, acting as a neutral arbiter between competing theories.
Philosophers of science tend to understand evidence not as mental states but as observable physical objects or events, secured by following the scientific method.
[1] The relation between evidence and a supported statement can vary in strength, ranging from weak correlation to indisputable proof.
Reference to evidence is made in many different fields, like in science, in the legal system, in history, in journalism and in everyday discourse.
This line of thought is usually followed in epistemology and tends to explain evidence in terms of private mental states, for example, as experiences, other beliefs or knowledge.
[7][8][11][12][13] Another intuition, which is more dominant in the philosophy of science, focuses on evidence as that which confirms scientific hypotheses and arbitrates between competing theories.
This leaves publicly observable phenomena like physical objects and events as the best candidates for evidence, unlike private mental states.
[16] Important theorists of evidence include Bertrand Russell, Willard Van Orman Quine, the logical positivists, Timothy Williamson, Earl Conee and Richard Feldman.
[8] Russell, Quine and the logical positivists belong to the empiricist tradition and hold that evidence consists in sense data, stimulation of one's sensory receptors and observation statements, respectively.
The more common view is that all kinds of mental states, including stored beliefs that are currently unconscious, can act as evidence.
The idea behind this line of thought is that justified belief has to be connected to or grounded in the mental state acting as its evidence.
[29] This evidence-based method is meant to make it possible for philosophy to overcome many of the traditionally unresolved disagreements and thus become a rigorous science.
These requirements suggest scientific evidence consists not of private mental states but of public physical objects or events.
[8] Logical positivists, on the other hand, held that this priority is semantic in nature, i.e. that the meanings of the theoretical terms used in the hypothesis are determined by what would count as evidence for them.
Counterexamples for this view come from the fact that our idea of what counts as evidence may change while the meanings of the corresponding theoretical terms remain constant.
[33][34] So, for example, evidence from our everyday life about how gravity works confirms Newton's and Einstein's theory of gravitation equally well and is therefore unable to establish consensus among scientists.
[38] Theory-ladenness threatens to impede the role of evidence as neutral arbiter since these additional assumptions may favor some theories over others.
[7][41] Probabilistic approaches, also referred to as Bayesian confirmation theory, explain the evidential relation in terms of probabilities.
Instead, various auxiliary assumptions have to be included about the location of the smoke, the fire, the observer, the lighting conditions, the laws of chemistry, etc.
But many scientific theories posit theoretical objects, like electrons or strings in physics, that are not directly observable and therefore cannot show up in the evidence as conceived here.
[7][14] In scientific research evidence is accumulated through observations of phenomena that occur in the natural world, or which are created as experiments in a laboratory or other controlled conditions.
Evidence and rules are used to decide questions of fact that are disputed, some of which may be determined by the legal burden of proof relevant to the case.
[50] The path that physical evidence takes from the scene of a crime or the arrest of a suspect to the courtroom is called the chain of custody.
In law, certain policies allow (or require) evidence to be excluded from consideration based either on indicia relating to reliability, or broader social concerns.
Conclusions drawn from evidence may be subject to criticism based on a perceived failure to fulfill the burden of proof.
Two principal considerations are: The latter question depends on the nature of the point under contention and determines the quantity and quality of evidence required to meet the burden of proof.
In a criminal trial in the United States, for example, the prosecution carries the burden of proof since the defendant is presumed innocent until proven guilty beyond a reasonable doubt.
Similarly, in most civil procedures, the plaintiff carries the burden of proof and must convince a judge or jury that the preponderance of the evidence is on their side.
In a philosophical debate, there is an implicit burden of proof on the party asserting a claim, since the default position is generally one of neutrality or unbelief.
