User:Manuela.Irarraz/sandbox/Approaches to Knowledge/ Seminar Group 8/Evidence

Evidence

Evidence, in a broad sense, is available information that supports the validity of a proposition.

Evidence plays a crucial role in the way we can attain truth, however when one tries to define it, they might find themselves troubled. Indeed, evidence in its various shapes and forms can at time seem contradictory, as scientific well founded facts can be considered evidence in the same way examples from our daily and personal experiences can too.

What matters, however, when we are in search for a conclusion or for truth is the way in which we apply evidence to our issue or question; it is a, in a sense a question of using the correct tools and instruments.

If one is to call evidence an instrument however, it must mean that at some point we are to have collected enough of it to insure our truth cannot be questioned. This raises the second issue one may face with evidence: how much evidence is enough evidence?

Furthermore, when answering a question it is important to note which kind of evidence is used; the use of a specific evidence can influence results as well as bypass other, possibly crucial information points.

[intergrate text below into introduction?]

• "Quine, the greatest empiricist of the second half of the century, maintained throughout his career that evidence consisted of the stimulation of one's sensory receptors"
• Generally defined as facts, data and information that allows one to come to a consensus upon the veracity of a statement. However due to the cross disciplinary nature of evidence, its definition may vary from one subject to another.

Definition and Etymology

"And when we try to define ‘evidence’ … we find it very difficult."

  —R.G. Collingwood The Idea of History

Evidence has different leanings in the English language - it is defined as ‘the available body of facts or information indicating whether a belief or proposition is true or valid’. In a law context, it is an object used to establish facts in a legal investigation; information in the form of a personal testimony, document or material object. It is also used when describing signs or indications of something.

The word evidence stems from the Latin evidentia. In classical Latin, it possesses the meaning of “distinction, vivid presentation, clearness”, in Late Latin “proof” and in Latin rhetoric, the word evidens carries the meaning “obvious, apparent”. Thus it is closely linked to the word evident.

Different Approaches To Evidence

Evidence as Sense Data

Russell, the greatest empiricist of the first half of the twentieth century, tended to think of evidence as sense data, mental items of one's present consciousness with which one is immediately acquainted. On this picture, evidence is affected by one’s psychological state, memory and experiences which isn’t always a reliable source. An example of this is a wrong eyewitness identification. Jenniffer Thompson is a North Carolina rape victim whose eyewitness identification of a suspect put the wrong man in prison for life. “Again, I was sure. I knew it. I had picked the right guy, and he was going to go to jail. I was certain, but I was wrong.” Thompson’s mental state and her memory at that time deceived her perception which brings on false evidence.

Evidence as the totality of propositions that one knows

According to one recent and influential study, one's evidence consists of the totality of propositions that one knows (Williamson 2000) There are many questions that rise up with this such as: “How do we justify one’s knowledge, What’s the limitation of one’s knowledge”. There are many ways to acquire knowledge like perception, emotion, reason and memory. Sometimes the way we acquire knowledge is not trustworthy.

Evidence as That Which Justifies Belief

Evidence is also defined as something that can make a difference to what one is justified believing. Plato famously defined knowledge as "justified true belief". According to his definition knowledge requires three irreplaceable key factors which are: truth, belief and justification. Evidence is seen as what justifies belief thus evidence is what builds reliable and justified knowledge up. We can’t access reliable knowledge without necessary evidence.

The relationship between truth and evidence “Evidence as a Way to Access Truth”

In general, we rely on evidence in cases in which our access to truth would otherwise be problematic. If evidence consists of facts or known propositions, then no body of evidence rules out any truth. We seek to believe what is true by means of holding beliefs that are well-supported by the evidence, and we seek to avoid believing what is false by means of not holding beliefs that are not well-supported by the evidence.

Subjective nature of evidence “Reliability of Evidence"

Spheres of Evidence

We can only access truth by reliable evidence but to what extent evidence is reliable? Figure 1 illustrates the process and circle of evidence. As shown in the diagram all existing evidence is provided by reality, (which is acquired through are senses) explorations and research. When evidence gained is published and displayed potentially available evidence emerges. However, all available evidence is not accessed because of the selection of evidence and curation. As demonstrated in the diagram while gaining and using evidence; one's worldview, beliefs, cultural influences affect their selection of evidence which causes subjectivity in evidence. One may only access the evidence which confirms what one believes which is often called confirmation bias. One common form of confirmation bias is for a scientist to dismiss results they don't expect as experimental error. Gregor Mendel, who laid the foundations of genetics, has been accused by some of only reporting results that favoured his case as his results supported his hypothesis and laws too accurately. On the other hand we can look this circle in a different way in which our worldview and beliefs are shaped by the evidence displayed. Philosopher Blanchard said: "What is creditable … is not the mere belief in this or that, but the having arrived at it by a process which, had the evidence been different, would have carried one with equal readiness to a contrary belief."

According to Russel's argument, evidence is what we acquire thorough our senses which can be called as empirical evidence. Empirical evidence is used as a scientific method which is mostly based on observations. The accuracy of empirical evidence is debatable since there are some problems with observation as the following:

Observer Effect

The observer effect is the theory states that simply observing a situation or phenomenon necessarily changes that phenomenon. An especially unusual version of the observer effect occurs in quantum mechanics, as best demonstrated by the double-slit experiment. Physicists have found that even passive observation of quantum phenomena can actually change the measured result. Also, the equipment used to measure something can also affect the experiment. This theory can also be applied to psychology and sociology. In this sense people change their behaviour when they know they are being observed. For instance, students study harder when they know they are being graded by their teachers.

Expectations

Sometimes a scientist's expectations interfere their observations so that they might ignore what they perceived. For example, if you look at a leaf under a microscope and asked to draw it, your drawing may be influenced by what you learned earlier in the biology class.

Fallibility of sense perception and sense perception based evidence

Nevertheless, sense perception can be deceptive. There is the case of Donald Gates who was wrongly accused of murder and rape of a student, and later exonerated when it was found that the testimony was based on faulty hair analysis.

Some questions that should be discussed:

• What is eligible to count as evidence?
• To what extent do we need evidence for our beliefs?
• Ad ignorantiam fallacy: It is claiming that something is true because there is no evidence that proves them to be false. So people can claim that there are ghosts because you can’t disprove their existence. If you claim that you need no evidence to support your claim you commit this fallacy.

Different Approaches to Prove 'Truth'

There are two simple ways in which evidence can be used to prove that a certain statement is truth or not. One is based on verifiability and the other on falsifiability. If evidence A supports hypothesis X, then it can be said that evidence A makes it more likely for X to be true. In this case, verification is used to confirm and show that the hypothesis holds true; the evidence 'verifies' the hypothesis. Alternatively, if evidence B is against hypothesis X, evidence B is making hypothesis X less likely to be true. Here, the evidence is disconfirming the hypothesis, and is trying to reach truth by falsifying the hypothesis. In a real-life situation, verification of a person being in restaurant A at 8 O'clock would be a photo of the person in the restaurant with the clock's hand pointing at 8:00 in the background, which proves that the fact is true. On the other hand, falsification of this same situation would be a GPS record of the person at a park at 8 o'clock, which proves that the fact is false.

Evidence and Disciplines

Evidence in Natural Sciences

Experiments are used in the natural sciences in order to test theories, in order to provide refinements or displace a theory entirely, hence acquire knowledge. Experiments are useful because it can produce evidence that can be used to adjust a current theory, by showing results which are against it or observations that calls for an explanation. However, not all experiments carried out produce results that provide straight forward evidence, some may create dispute with other experiment results or be entirely wrong.

Evidence in Social Sciences

Social scientists have taken a more qualitative approach when generating evidence. The research methods which social scientists have adopted includes questionnaires and opinion polls.

However, some social scientists are adopting new research methods as King has suggested that some methods of generating evidence in the social scientists have become outdated. For example when learning about human population the sample survey has been a used as an important research tool, King has stated that this research method has been limited as is not representative of whole communities. Similarly, Savage and Burrows have stated that the use traditional research methods in the social sciences has resulted in a decline in interest due to poor response rates to surveys and opinion polls.

Evidence in Religion

Many choose to believe in a religion for various reasons, however, evidentialists may view belief as an irrational behaviour unless evidence is provided. Reformed epistemologists have opposing views, in which they see evidence for belief arises from the belief itself, such as belief in God, is evidence itself.

Reform epistemologist Alvin Plantinga explains there might not be solid evidence for the existence of God, although his existence is proven through moral thoughts we have. Such that, when one does wrong, the feel of guilt is the presence of God reminding of one that is an action of sin.

Evidence in Mathematics

Evidence in the eyes of mathematicians and society regarding mathematics lies in 'mathematical proof'. A mathematical proof proves the truth in a statement using definitions, theorems, and postulates, with no room for assumptions. Mathematical proofs use deductive reasoning by drawing a conclusion from multiple premises. Deductive reasoning is essentially watertight - a premise from which the conclusion is drawn would have to be deemed incorrect for the conclusion to be inaccurate. Therefore, in mathematics, deductive reasoning is crucial to prove that the derived mathematical rule or formula is true in every situation and for eternity. The significance of foul proof deductive reasoning dates back to the ancient Greeks. Euclid of Alexandria, deemed the 'father of geometry', created a book of axioms which he referred to as 'common notions', statements he believed to be eternally true requiring no further justification.

Mathematical proofs can be either direct or indirect. A direct proof uses statements to prove that the conclusion is in fact true. On the other hand, an indirect proof proves a statement by use of contradiction.

Evidence in Law

Evidence in Law is based around the compilation of tangible or immaterial objects related to a specific crime which in time is to be ratified by a jury or used for the purpose of investigation. Needless to mention, the use of evidence in law is heavily significant to determine the truth and whether the suspect is guilty of the crime or not. Hence, admissible evidence is strictly governed throughout the course of judicial processes;this is also known to be the Federal rules of Evidence. These rules exist to avoid potential distraction of the court, preventing the introduction of distracting facts to the jury. One important criteria that evidence in law is assessed on, is relevance. This simply means that the there must be a logical connection between the presented evidence and the premise that it is trying to make. Although this relevancy of evidence plays a huge rule through evidence law, it is not the only criteria; relevant evidence might be excluded due to existing prejudice and cumulative. Another guideline in evidence law, are rules against opinions. Opinions can be shared in the court throughout hearsay and testimony; both can provide eye witnesses or general statements made by an individual. They are personal thoughts; hence, they cannot be perceived and used as evidence. Reasons for this unreliability of testimonies include multiple fallacies of evidence (more outlined below) such as the ad-hominem fallacy, where a person possesses an opinion that attacks the individual, rather than their argument.This fallacy is also another reason why there are strict regulations against permitting character evidence to be used in court. The jury has the right to neglect any testimonies or hearsays that are opinion-based rather than facts. Moreover, the character evidence tends to be weak as people do not often act in a certain way accordingly to their perceived characteristics and personality. Witnesses testimonies in general, are highly influenced by their distorted memory which can be effected from traumas or post-event information, which is why they are likely to lead to misjudged statements about the person.

Types of evidence in Law

• Demonstrative Evidence

Usually in the form of a physical object; this form of evidence is a common form of proof used in court cases. Some examples include photographs, footage, audio tapes, etc.

• Digital Evidence

This type of evidence has increased over these few years as of the development of electronic devices and technology. Digital evidence refers to proof that is taken from an electric source, such as emails, hard drives, ATM recordings, etc.

• Exculpatory Evidence

Refers to evidence that favors the accused, either supporting their innocence or in some cases, completely prove it. Such evidence is typically presented in criminal cases.

• Prima Facie Evidence

Evidence that is so strong and sufficient that it can prove a certain preposition to be true, but is refutable by later evidence.

Scientific Evidence in Law

Scientific evidence is developed from knowledge that is gained through scientific methods. In general, forensic evidence such as genetic hair evidence, DNA matching, fingerprint identifications, etc. are considered as scientific evidence. These evidence presented to the court, are usually beyond the knowledge that the jury has, and is therefore, labeled as scientific evidence. Scientific Evidence that is authorized and admitted by a scientific community, can be presented in court as evidence as long as its reliability is insured by the jury. In order for the scientific evidence to be approved before it is presented to the court, the data (which the evidence is based on) must be published or present in scientific journals and assessed by scientific peers who are qualified. This is a significant and crucial part of the process, as it is the only method to check the validity of scientific methods and reliability of their findings. This general process in which scientific evidence is accepted in law courts, is known and can be explained through the Frye test.This type of test was derived from the case of James Frye who was put on trial for murder in 1923; Frye v. United States (1923). During his testimony for defense, he provided a testimony of an expert who proved that Frye was speaking of truth when he rejected culpability, through a blood pressure test that determined if he was lying or not. This test which involved a scientific method, became the standard for most testimonial judgements at the time, meaning that the evidence given by the Frye test gained scientific consensus, in other words, general acceptance from the scientific community in which the expert's specialty existed in. The Frye Test thereby pertains to the admissibility of testimony relied on scientific methods.

However, the Frye test was no longer acknowledged as the criteria to access scientific evidence, as the United States Supreme Court case, Daubert v. Merrell Dow Pharmaceuticals., was introduced in 1993. The Daubert test projects the admissibility of testimonies by scientific experts like the Frye test, although it has a new set of criteria for itself, which became the standard at this time. There are four main factors for admissibility of expert testimony in the [Daubert test]. First, if the scientific methods that the testimonies are based on, are established upon a testable hypothesis. Testable, also implying that the hypotheses are actually 'tested' throughout the process. Second, the level of potential errors of the methods. Third, if the methods have been through peer assessment or not. Fourth, whether the methods are admitted and approved by scientific communities or not. The first two criteria of the Daubert test was established by Daubert, and centers its focus on tested and hypothesized scientific evidence, requiring expert testimony to be derived from 'scientific methods'. The Court's discussion about scientific methods mentions this necessity of hypotheses and testing as follows:Scientific methodology today is based on generating hypotheses and testing them to see if they can be falsified; indeed, this methodology is what distinguishes science from other fields of human inquiry. Hypothesis testing is the derivation of a certain proposition that is set in regards to an observational event/s from scientific principles, that is, through investigation and evaluation of observational data, decided to be true or not. As hypothesis testing has the ability to distinguish non-scientific methods to scientific methods of inquiry, Daubert test is utilized as a proxy for admissibility of scientific evidence, and is applied in the Federal Rules of Evidence as well.

In Medicine

Indeed, although many may adopt a skeptic stance, anecdotal evidence may prove itself very useful depending on the situation it is applied to. Take as example the field of medicine, at first glance one may find it hard to see the use of anecdotal evidence in such a scientific minded field, where rules a normative use of data and theoretical knowledge in order to pin-point the illness. However, illness and its effects, as communicated by the patient is done through the use of anecdotal evidence. If you were to ask a range of patients what level the pain they were feeling was at on a scale, the answer would vary from individual to individual, as would their pain threshold. Here, the information we are given by the patient is of subjective nature and we can therefore see the importance of anecdotal evidence in the field of medicine, indeed, anecdotal evidence allows doctors and physicians alike better insight to the patients condition.

Although today 'Evidence- based medicine' or EBM is taken as canon throughout the medical world (and therefore putting anecdotal evidence to the back of the stage), the first medical writings of it are dated in1992 following research made by Gordon Guyatt and David Sackett. The rise of evidence- based medicine is interesting as through its own name it denigrates anecdotal and subjective points of view, and changes in a certain aspect the way we view a patient.

Evidence in Philosophy

Evidence has been discussed greatly in Philosophy, of which different definitions have arose as a result. In the first half of the 20th century, Bertrand Russell suggested that evidence was a form of "sense data" that a person harbours in their current state, and becomes familiar with. Quine, in the second half of the 20th century, later proposed that something was deemed as evidence if they "stimulated one's sensory receptors", which is evidence that something is proven to exist.

Generally, in Philosophy, what classifies as Evidence varies dependent on the nature of the discussion. Such evidence have included 'experiences, propositions, observation-reports, mental states, states of affairs, and physiological events'.

Evidence in History

In history, we can know the past only to the extent we have evidence for it. Historians make sense of the past by looking into different evidences such as primary sources, secondary sources and oral history. Primary sources can be either written documents or visual sources, such as art, photographs, and artifacts. Like lawyers who present evidence to make their cases before judges and juries, historians use the evidence they uncover in their research to help prove their interpretations of the past. Historical interpretation is one particular view or theory based on historical evidence. In order for interpretation to be proposed convincingly, some degree of evidence must be present. Some historians take the same evidence but arrive at different conclusions. For example, Franklin Roosevelt’s New Deal is still a controversial topic in history. Even though, historians have the same evidence, their interpretation of the plan used to recover from the Great Depression is different. While some historians argue that it was a failure, others believe that it was beneficial. In trying to reconstruct the past based of the evidence, one of two problems may arise: too little evidence, or too much evidence. For example, our knowledge of the wars between Persia and Greece in the fifth century BCE is based on a single, quite unreliable, source: the Greek historian Herodotus. In Book One of The Histories, when Herodotus describes the physical and political atmosphere in Persia, he greatly exaggerates how massively fortified the city of Babylon is. According to Herodotus, the city of Babylon had “magnificence greater than all other cities of which we have knowledge.” He claims that 100 bronze gates were erected at the entrance of Babylon. However, archaeological evidence tells us that Babylon had eight gates, not 100, and was not as grand as Herodotus boldly claimed. When it comes to contemporary history, we are faced with too much evidence from internet and media which may be biased and unreliable.

Another tool that historians use is oral history. This is made up of all the unwritten verbal accounts of events. Historians depend on oral history when studying cultures that have no written records. Oral histories include the stories, customs, and songs that people in a culture have passed down from generation to generation. Oral history may not be reliable source. Imagine two people that witnessed the same historical event. The evidence gained from two people would probably differ because of their interest, memories and cultural background.

Types of Evidence

Empirical evidence

Empirical is derived from the Greek word experience and the evidence is produced through observation and experimentation. Empirical evidence is a fundamental part of the ‘scientific method’ in which experiments are designed and repeated to produce data which is analysed to develop a theory.

Within the social sciences the methodology of observation is used to produce empirical evidence, the evidence produced in the social sciences is frequently qualitative as this helps the scientist form a better understanding of human behaviour. Whereas within the natural sciences quantitative data is produced through experimentation which is then tested for statistical accuracy in order to develop a hypothesis.

Theoretical evidence

The purpose of theoretical evidence is to develop knowledge to establish a principle/theory which contributes to the understanding of an aspect within the discipline. The development of a theory condenses knowledge through connecting already established ideas, this therefore aids the development of new research.

Inductive and deductive reasoning are fundamental methodologies in the production of theoretical evidence. Deductive reasoning is based on using previously developed theory in order to guide the direction of empirical evidence and to the aid the interpretation of empirical evidence. Whereas the inductive approach is based on a ‘bottom up’ perspective in which hypotheses are developed from an observation through observing patterns which then aid the emergence of a theory.

Anecdotal evidence

Unlike most evidence, anecdotal evidence isn't based on proven facts and data collection, rather, it can be defined as evidence specific to a persons experiences, or observation, often retold in the shape of a story.

The use of anecdotal evidence raises many questions about the specificity of evidence in the optic of truth. Indeed, when it comes to applying anecdotal evidence to the real world, one may ask himself whether it is notable enough a source, in terms both of quality and quantity.

Evidence in Forensic Science

In forensic sciences, evidence can be used in court to support criminal proceedings. Forensic evidence is generally obtained through scientific methods such as blood tests and DNA tests. It is used to identify possible suspects and is used to support their innocence or their guilt. Evidence in forensic science is very closely linked to evidence in law, as forensic evidence is generally obtained to support legal proceedings.

Not all forms of forensic evidence is admissible in court. For example, in the United States, There are currently some guidelines that determine forensic evidence admissibility, such as the Frye standard (also known as the general acceptance test), which we have touched on in the section on Evidence in Law, and the more recent Daubert Standard. The Frye standard determines that in order for the evidence to be admissible, the thing from which it is deducted from must have been obtained in a way that is generally accepted by the relevant scientific community. The Daubert standard expands on this general acceptance by allowing cross-examination, presentation of contrary evidence and further instructions on the proof of shaky evidence. Expert testimony is therefore sometimes not enough to be admissible in court.

How evidence is obtained, deducted and later used to support a proposition in forensic science is an interesting example of how evidence is subject to different standards of validity, and what constitutes as 'evidence' is still debatable.

Arguments and evidence

Cosmological Argument

The Cosmologcial argument demonstrates God’s existence through the use of logic and deductive reasoning. The cosmological argument was developed by Thomas Aquinas who argued God’s existence through using a scientific an approach and scientific evidence. Aquinas set up five arguments to demonstrate God’s existence, four of which are known as the cosmological argument:

Argument of motion: Aquinas argued from observations and through the study of Aristotle’s work that we live in a world surrounded by movement and that this movement must have been started by another object in motion otherwise we would have an infinite regress which argues that there was no starting point. According to Aquinas, God started the motion as he is a non-mover.

Causation of existence: This argument is based off the principle that objects are created by other existing objects and that there cannot be an infinite regress of causes so therefore there is an uncaused first cause which Aquinas argued that this was God.

Argument for contingency: Argues that there is contingent beings and necessary beings. A contingent being is contingent on the existence of others. Aquinas believed that there would be an existence of something which prevented an infinite regress of contingency so therefore a necessary being had to exist (a being which has always existed) to produce the contingent beings which Aquinas argued was God.

Argument from degrees: This argument is based from Aquinas’s observation that different objects have different degrees of qualities, for example one object is large and the other is small. Aquinas argued that for degrees of perfection to exist there must be a perfect being and that this being was God.

Ontological Argument

Ontological arguments are points of view which concludes God's existence through reasoning alone, with no inputs from observation. The very first idea began in the 11^th century, when the belief that no being is greater than God can possibly exist therefore God must exist, was proposed by St. Anselm of Canterbury. Many centuries later, Descartes backed the idea that God must exist due to necessity, as supreme perfect being has to exist because of its divinity.

Evidence and paradigm shift

A paradigm shift, a concept identified by the American physicist and philosopher Thomas Kuhn, is a fundamental change in the basic concepts and experimental practices of a scientific discipline. As basic concepts and experimental practices are changing, the evidence that is used to prove the previous knowledge can be altered. For example, during the Middle ages, everyone thought that they knew that there were seven planets orbiting the earth (Sun, Moon, Mercury, Venus, Mars, Saturn and Jupiter) and they probably had the evidence to support their argument. Three years back from now we had enough evidence to prove that there are 9 planets including Pluto. Now we know that there are 8 planets orbiting the sun. Knowledge changes as time goes by and so does evidence.