Argumentum ad Verecundiam

We normally expect writers to cite evidence in support of their argument from authoritative (expert) sources; however, there are four types of authority evidence which are considered faulty:

• where the source is not qualified to have an expert opinion in the field,
• where experts in the field disagree on the issue,
• where the source was not serious (for example, a joke or while drunk), and
• when it is hearsay (second hand information).

The hearsay rule is that second hand evidence (or worse) is generally inferior to primary evidence except where one of the thirty hearsay exceptions applies. Such evidence is so inferior, that it is generally inadmissible in judicial proceedings.

Examples:

Noted psychologist Dr. Frasier Crane recommends that you buy the EZ-Rest Hot Tub. (Psychologists are seldom experts in hot tubs)
Economist John Kenneth Galbraith argues that a tight money policy is the best cure for a recession. (Although he is an expert, not all economists agree on this.)
Ronald Reagan once remarked that the United States will begin bombing Russia in five minutes. (Reagan said it as a joke during a microphone test.)
My best friend told me he overheard his neighbor say that he personally saw the thief running away. (Third hand hearsay)

Strategy: Identify the evidence and its source and show that he or she is not an expert in the field, that other experts in the field disagree, that the statement was not intended to be taken seriously, or that the evidence is second hand hearsay and not subject to any of the hearsay exceptions.

Hearsay exceptions: The following are the thirty generally recognized hearsay exceptions. The reason why these exceptions are allowed is that, over time, experience has proven that certain kinds of information cannot be reasonably obtained in any other way or that certain types of evidence is most probably true because it is phenomenally difficult to fabricate later. If you watch court room dramas on television or the movies (or actually observe a real trial), you will frequently hear these raised as responses to hearsay objections. Of course, any of the exceptions can be overcome by a showing of substantial conflicting primary evidence.

1. Present Sense Impression--any statement describing or explaining an event or condition made while perceiving the event or condition, or immediately thereafter.
2. Excited Utterance--any statement relating to a startling event or condition made while under the stress of excitement caused by the event or condition.
3. Then Existing Mental, Emotional, or Physical Condition--any statement of the then existing state of mind, emotion, sensation, or physical condition.
4. Statement for Purposes of Medical Diagnosis or Treatment--any statement made for purposes of medical diagnosis or treatment.
5. Recorded Recollection--any memorandum or record concerning matter about which someone once had knowledge but now has insufficient recollection.
6. Records of Regularly Conducted Business Activity--any memorandum, report, record, or data compilation, in any form, of acts, events, conditions, opinions, or diagnoses, made in the course of a regularly conducted business activity.
7. Absence of Entry in Records of Regularly Conducted Business Activities--any evidence that a matter is missing from the memoranda, reports, records, or data compilations, in any form, of a regularly conducted business activity, specifically intended to prove the nonoccurrence or nonexistence of the matter.
8. Public Records and Reports--any record, report, statement, or data compilation, in any form, of public offices or agencies, setting forth the activities of the office or agency or matters observed within the scope of  its agent's or employee's duties.
9. Records of Vital Statistics--any records or data compilations, in any form, of births, marriages, or deaths maintained by a public agency..
10. Absence of Public Record or Entry--any evidence offered to prove the absence of a record, report, statement, or data compilation, in any form, or the nonoccurrence or nonexistence of a matter of which a record, report, statement, or data compilation, in any form, was regularly made and preserved by a public office or agency.
11. Records of Religious Organization--any statement of birth, marriage, divorce, death, parentage, ancestry, relationship by blood or marriage, or other similar facts of personal or family history, contained in a regularly kept record of a religious organization.
12. Marriage, Baptismal, and Similar Certificates--any statement of fact contained in a certificate that the maker performed a marriage or other ceremony or administered a sacrament, made by a clergyman, public official, or other person authorized to perform the act.
13. Family Records--any statement of fact concerning personal or family history contained in family Bibles, genealogies, charts, engravings on rings, inscriptions on family portraits, engravings on urns, crypts, or tombstones, or the like.
14. Records of Documents Affecting an Interest in Property--any document purporting to establish or affect an interest in property as proof of the content of the original recorded document and its execution and delivery by each person by whom it purports to have been executed.
15. Statements in Documents Affecting an Interest in Property--any statement contained in a document purporting to establish or affect an interest in property.
16. Statements in Ancient Documents--any statement in a document in existence twenty years or more where the authenticity of the document has been established.
17. Market Reports, Commercial Publications--any market quotations, tabulations, lists, directories, or other published compilations, generally used and relied upon by the public or by persons in particular occupations.
18. Learned Treatises--any statement contained in published treatises, periodicals, or pamphlets on a subject of history, medicine, or other science or art, when the same is established as a reliable authority. 
19. Reputation Concerning Personal or Family History--any evidence of reputation among members of a person's family by blood, adoption, or marriage, or among a person's associates, or in the community, concerning a person's birth, adoption, marriage, divorce, death, parentage, relationship by blood, adoption, or marriage, ancestry, or other similar fact of personal or family history.
20. Reputation Concerning Boundaries or General History--any evidence of reputation in a community, arising before the controversy, as to boundaries of or customs affecting lands in the community, and reputation as to events of general history important to the community or State or nation in which located.
21. Reputation as to Character--any evidence of reputation of a person's character among associates or in the community.
22. Judgment of Previous Conviction--any evidence of a judicial finding adjudging a person guilty of a serious crime. Sometimes called prior bad acts and are used to show a propensity to do something.
23. Judgment as to Personal, Family, or General History, or Boundaries-- any judicial finding as proof of matters of personal, family or general history, or boundaries.
24. Child's Statement About Sexual Abuse--any statement by a minor child about sexual abuse of that child or witnessed by that child.
25. Former Testimony--any sworn testimony given either as a witness during a court proceeding or in a deposition where the testimony was subject to direct, cross, or redirect examination by all interested parties.
26. Deathbed Statements--any statement made by a person while believing that his or her death is imminent. 
27. Statement Against Interest--any statement that was at the time of its making so far contrary to the maker's pecuniary or proprietary interest, or so far tended to subject the maker to civil or criminal liability or to render invalid a claim by the maker against another or to make the maker an object of hatred, ridicule, or disgrace, that a reasonable person in the maker's position would not have made the statement without believing it to be true. 
28. Statement of Personal or Family History--any statement concerning a person's own birth, adoption, marriage, divorce, parentage, relationship by blood, adoption, or marriage, ancestry, or other similar fact of personal or family history.
29. Forfeiture by Wrongdoing--any statement offered against a party that has engaged in wrongdoing that was intended to, and did, procure the unavailability of a witness (evidence of witness tampering).
30. Residual Exception--any circumstantial evidence offered as evidence of a material fact where the statement is more probative on the point for which it is offered than any other evidence and the interests of justice will best be served by its admission.