Presentation on theme: "Nature and Value of Evidence The key questions on which the validity, soundness, strength, or cogence of any argument rest are: What is the evidence? How."— Presentation transcript:
Nature and Value of Evidence The key questions on which the validity, soundness, strength, or cogence of any argument rest are: What is the evidence? How good is the evidence? The quality of an argument depends on the quality and quantity of the evidence used to support the conclusion and premises. The value of evidence is determined by three qualities: pertinence (relevance) verifiability (corroboration) sufficiency (weight) In hierarchical terms, the value of evidence is considered on the basis of three broad classifications or types: fact authority logic In fact, this hierarchy is only theoretical, for a true assessment of the quality of evidence is invariably circumstantial and unpredictable.
Fact Fact is considered to be the most valuable evidence because of its perceived greater objectivity or tangibility. Fact (derived from the Latin word factum, meaning something done or performed), according to standard dictionary definition, is something that actually exists has really occurred is the case has objective reality that can be verified according to an established standard of evaluation. Fact is sometimes used as synonym for “truth” or “reality,” as distinguishable from conclusions or opinions – as a “matter of fact.”
Indisputable Fact In its purest form, a fact is an indisputable claim, as in the following example: President John F. Kennedy was assassinated in Dallas Texas on 22 November 1963. Reasonable people do not dispute this factual claim. In other words, the truth of this statement has been accepted so widely that it is considered an absolute fact. No evidence needs to be offered to support this claim, and indeed, this fact can reasonably be offered to support another claim related to the prevalence of political violence in the United States.
Disputable Fact The following factual claim is disputable: Lee Harvey Oswald assassinated President John F. Kennedy in Dallas Texas on 22 November 1963. While some history books and mainstream media commentators would consider this claim to be a fact, many knowledgeable and reasonable people dispute the part of the claim that identifies Oswald unconditionally as the assassin. The addition of the conditional adverb "allegedly" before the verb "assassinated" may acknowledge the potential for dispute of the claim, but it does not alleviate the disputed nature of the statement. Evidence will be required to support this claim. A factual claim, therefore, represents a belief, either in the form of a conclusion, a reason, or an assumption, which may or may not require the support of evidence, depending on the nature and extent of the consensus that prevails regarding the belief.
Relativity of Fact Fact may be argued under the authority of a specific pedagogy or discipline, such science or history. Fundamentally, a scientific “fact” is an objective and verifiable observation, in contrast to a “hypothesis” or “theory,” which is intended to explain or interpret facts. In the proper application of the scientific method, facts are generally believed to be independent of the observer: no matter who performs a scientific experiment, all observers will agree on the outcome. Accordingly, the truth of scientific facts will change over time to reflect the current consensus. Similarly, the truth of historical fact is ever changing and elusive because of the inherent biases at work in the gathering of facts – all compounded over time. The tendency of historians to interpret the past based on perspectives of the present renders objective truth unattainable. In general scholarly terms, facts tend to be equated with findings derived through a process of evaluation, as distinguishable from matters of inference or speculation.
Fact as Physical Evidence In legal cases, the strength of fact is accentuated by its connection to science or tangible reality. Forensic science and crime scene investigation rely heavily on physical evidence. Physical evidence = DNA, fingerprints, fibres, ballistics, autopsy findings, among other “on the scene” data. Physical evidence is supported by the presumed objectivity of science, if not the scientist. Effectiveness is ultimately dependent on the integrity and skill of the handler or interpreter of such evidence. WC supporters like to point to the primacy of physical evidence, without necessarily evaluating its handling and/or interpretation.
Fact vs Assertion or Theory A factual claim that requires evidence but is not supported by any is referred to as an assertion. A mere assertion is not considered "dependable" because of the lack of supporting evidence. The major difference between claims that are assertions or opinions and those that are facts is the present state of the relevant evidence. Misunderstanding may also exist between fact and theory (or opinion). In a scientific context, a theory is a generalized explanation resulting from rational thinking and empirical evidence – Big Bang Theory or Pythagorean Theory. In more common terms, a theory can simply be a generalized explanation that is unproven or speculative. In 2003, Arlen Spector argued that the "single-bullet theory" was now the "single-bullet fact" because it had become so indisputable. He is confusing fact to mean "truth" and theory to mean “speculation.” The greater the quantity and quality of evidence supporting a claim or belief, the more dependable and thus “factual” it becomes. In essence, the nature of fact is relative – in the eyes of the beholder.
Single-bullet theory (SBT) $ Only 3 shots were fired $ 1 shot entered the back of Kennedy’s head, inflicting a fatal wound. $ 1 shot missed completely, injuring bystander James Tague on the ricochet. $ 1 shot remains to inflict 2 wounds in Kennedy and 5 in Connally. SBT is the crux of the Warren Commission Report and the keystone to the lone gunman conclusion. Kennedy and Connally were hit by same bullet or a second gunman was firing a 4 th shot
Inductive Reasoning The single-bullet theory is a strong inductive argument because the five premises on which it is based pertain to the conclusion. But for the argument to be cogent (acceptable), all of the following premises must be true: Only three shots were fired from the Texas School Book Depository The body wounds of Kennedy and Connally were inflicted almost simultaneously. The seating positions of Kennedy and Connally were aligned with the bullet trajectory. The wounds suffered by Kennedy and Connally were aligned with the bullet trajectory. CE 399 found on Connally’s stretcher at Parkland Hospital Memorial was the bullet that passed through Kennedy and Connally.
Limited time frame in which to operate the gun The Mannlicher-Carcano 6.55 required at least 2.3 seconds between shots to operate by an expert and without allowing for re-aiming. Warren Commission claims the first shot could have come as early as frame 210 of the Zapruder film because trees blocked the possibility of an earlier shot. Connally shows first signs of reaction to gunshot wound at Z236-Z238 or 1.4-1.6 seconds after Kennedy was shot. Warren Commission also claims that the first shot could have come as late as Z225, thereby lessening the interval of interaction, but reducing the operation time between shots. In either scenario, both men could not be hit by separate shots without a second gunman, and thus a conspiracy.
Evidence disputing simultaneous wounding The later scenario allows the Warren Commission to argue in terms of simultaneous wounding by the same shot. FBI and Secret Service investigation contend that Kennedy and Connally were hit by separate bullets, thereby ignoring the missed shot. In his Warren Commission testimony, Connally insists that he heard the first shot and had time to turn around before being hit by second shot. Dr. Robert Shaw, the attending physician, disputes the Warren Commission claim that Connally suffered a “delayed reaction” to his wounds; he insists that the wounds were too severe for a delayed reaction. Forensic Pathologist Cyril Wecht concurs with Dr. Shaw. A single-bullet scenario is the WC’s only salvation.
Seating alignment problem between Kennedy and Connally Connally would have to be seated to the left of Kennedy (on his inside) to be in the proper line of trajectory. Connally is actually directly in front of Kennedy, according to the Zapruder film. Connally admits to turning to his right after the first shot and not seeing Kennedy out of the corner of his eye. The bullet in question violates the laws of physics by moving in various directions.
Wound alignment problem between Kennedy and Connally The official autopsy states that the bullet entered base of neck and exited from the front of throat. Dallas doctors Malcolm Perry and Champ Clark testified that the throat wound was one of entry – a small bullet hole (3 x 5 millimeters) on entry that becomes larger upon exit; they were influenced to change their minds by official pressure and autopsy findings. Official autopsy doctors missed the throat wound and did not follow proper procedure to trace the wounds and to consult with Dallas doctors; they referred to the throat wound “presumably” of exit and back wound “presumably” of entry. Autopsy doctors were not qualified; they were administrators who had rarely performed autopsies – one of worst medical legal autopsies according to Wecht. Whereas the autopsy doctors located the back wound at the base of the neck, Kennedy’s bloody shirt and jacket placed the bullet hole six inches lower in the shoulder blade. The death certificate signed by Admiral Burley, Kennedy’s personal physician, confirmed the lower location. The official autopsy body chart further confirms the lower location, which was changed upon discovery of throat wound. The autopsy doctors deliberately lied rather than being innocently mistaken; falsification essential to fit the lone-gun hypothesis
Dubious status of CE 399 (magic bullet) CE 399 is the only bullet purported to be a ballistic match to Oswald’s rifle, and thus the only piece of evidence to tie Oswald to shooting. The bullet allegedly passed through Kennedy’s neck and throat and through Connally’s rib and wrist bone, but remained in near perfect condition; it was only slightly flattened, consistent with firing through water or cotton. The Warren Commission tests conducted by Dr. Joseph Dolce confirmed significant deformity when bullets were fired through goat carcasses and human cadavres; the tip of the bullets were smashed. The bullet left fragments of metal in Connally’s body; more grains were removed from Connally than were missing from the bullet; it weighed 158.6 grains out of original 161 grains – losing only about 1% of its weight. Dr. Cyril Wecht’s challenge: find another example of a bullet that behaved like CE 399, which he claims is unprecedented in ballistic history. Without CE 399, there can be no single-bullet theory; without the single- bullet theory, there can be no lone assassin.
Conclusion The single-bullet theory was the foundation of the Warren Report. The single-bullet conclusion is progressively weakened by the fallacy (untruth) of its premises, and ultimately the Warren Report’s argument collapses under the uncogence of SBT. SBT is an incredible theory based on the assumption of Oswald’s guilt rather than on evidence derived from fact, authority, and logic. The Warren Report assumes the guilt of Oswald rather than his innocence, thereby reversing the burden of proof.