Question Database: Critical Thinking
Argument from authority: witnesses and experts
On leaving the pub at 1.00 am, the witness paused while looking around for a taxi. He then saw the accused leave the bar on the other side of the road, holding a knife and looking distressed. The witness had met accused once before and claims to have recognised him. The accused denies that he was at that bar at that time.
Which of the following statements concerning the reliability of the claims made by the witness are correct?
I. The claims are suspect because the witness knew the accused person.
II. The reliability of claims can be questioned because the witness may have been under the influence of alcohol.
III. The reliability of the witness is suspect because he was concentrating on something else at the time.
IV. The reliability of the claims can be questioned because the witness did not know the accused person very well.
A. I and II
B. II only
C. II and IV
D. II, III and IV
Answer: C
Topic:
Argument from authority. Testimony.
Course Level:
First year, critical thinking.
Notes:
I. There is no reason to suspect the reliability of the witness merely on the grounds that they knew the suspect (although a knowledge of the details of their relationship may well be relevant).
II. Since the witness was 'leaving the pub at 1.00 am', there is some reason to think they might have been drinking: people under the influence of alcohol do not make reliable witnesses.
III. This is not obviously relevant. Focusing on something else (such as looking round for a taxi) is likely to make people fail to see even quite dramatic events. If the witness was claiming not to have seen the suspect leave the bar, the fact that they were focusing on something else would make that claim unreliable. But this witness is claiming that they did see the suspect leaving the bar with a knife and recognised him, which suggests he was not distracted.
IV. The fact that witness had only met the accused once before weakens their claim to have recognised him. If it was someone the witness knew very well, their claim to have recognised the person would have more weight. How confident are you that having met someone only once, you could distinguish them from a similar looking person, across a dark street at 1.00 in the morning, especially if you'd been drinking for a few hours?