Report No. 69
Opinion of Experts
The difficult but important question of expert evidence is dealt with Introductory, in section 45. When the Court has to form an opinion upon a point of foreign law, or of science or art, or as to identity of handwriting or finger impressions, the opinions upon that point of persons specially skilled in such foreign law, science or art, or in questions as to identity of handwriting or finger impressions, are relevant facts.
Such persons are called experts.
17.2. There are three illustrations appended to the section. Illustration (a) relates to a case where the question is, whether the death of A was caused by poison. The opinions of experts as to the symptoms produced by the poison by which A is supposed to have died are relevant under the illustration. Illustration (b) relates to a case where the question is. whether A. at the time of doing a certain act, was, by reason of unsoundness of mind, incapable of knowing the nature of the act, or that he was doing what was either wrong or contrary to law.
The opinions of experts upon the question whether the symptoms exhibited by A commonly show unsoundness of mind, and whether such unsoundness of mind usually renders persons incapable of knowing the nature of the acts which they do, or of knowing that what they do is either wrong or contrary to law, are relevant. Under illustration (c), where the question is whether a certain document was written by A and another document is produced which is proved or admitted to have been written by A, the opinions of experts on the question whether the two documents were written by the same person or by different persons, are relevant.
17.3. Stephen's view.-
Sir James Stephen, in his 'Digest of the Law of Evidence', prefaces Chapter V in it on 'Opinions, when Relevant and When Not' with Article 481, which runs thus:
"48. The fact that any person is of opinion that a fact in issue, or relevant or deemed to be relevant to the issue, does or does not exist is deemed to be irrelevant to the existence of such fact. extent in the cases specified in this Chapter."
1. Article 48, Stephen's Digest.
17.4. The very next Articl.- Article 4.- sets out the important exception relating to opinions of experts, in the following terms:
"49. When there is a question as to any point of science or art, the opinions upon that point of persons specially skilled in any such matter are deemed to be relevant facts. Such persons are hereinafter called experts. The words 'science or art' include all subjects on which a course of special study or experience is necessary to the formation of an opinion, and amongst others the examination of handwriting."
17.5. Rule against opinion evidence.-
17.5. Section 45 creates an exception to the rule against evidence of "opinion". it is sometimes suggested that, in the English usage of the 18th Century, the word "opinion" had the primary meaning of "notion" or persuasion of the mind without proof or without certain knowledge, and not the modern use denoting belief, inference or conclusion, well or ill founded. Accordingly, the early English decisions prescribing1 opinion were designed to reject evidence not based upon personal knowledge : but not evidence of belief. Wigmore takes the view that until the beginning of the 19th Century, any witness was permitted to express his inference or conclusions from his own direct personal knowledge, or observation2.
But, thereafter.- certainly so far as lay witnesses were concerne.- the distinction between "fact" and "opinion" became established. It is, in many respects, a clumsy formula. "The rule in its stark simplicity might he interpreted as excluding all value judgments. that is to say, all statements not being factual propositions susceptible of some sort of empirical proof or disproof. The rule, if it is to be given any purely logical meaning at all, must be interpreted as excluding at least all inference drawn from perceived data. Even if value judgments are saved by construing the rule as having application only to factual propositions, the rule would seem to purport to exclude all such propositions in the formulation of which inference by the witness has played some parts"3. However, the general rule still holds good.
1. See e.g. Carter v. Boahm, (1766) 3 Burr 1905 (1918) per Mansfield, C.J., "It is mere opinion which is not evidence".
2. Wigmore, Vol. 7, Section 1917.
3. R. v. Fakir Mohammad, 1 CWN 33.
17.6. Identity of handwriting was added in the section, by an amending Act. The words 'finger impressions' were added by Act 5 of 1899, in consequence of the decision of the Calcutta High Court in R. v. Fakir Mohammad, 1 CWN 33, where it was held that the comparison of a thumb impression must be made by the Court itself, and that the opinion of an expert was not admissible under section 45. Under the amended section, evidence may now be given of finger impressions by an expert.
17.7. As regards finger-prints, it may be noted that in India. there are statutory provisions which authorise the police and the court to take fingerprints etc. of the accused, for purposes of comparison.
17.8. A police officer is authorised1 by the Identification of Prisoners Act, to take measurements (including finger-prints, foot-prints, and photographs) from any person arrested in connection with an offence punishable with rigorous imprisonment for a term of one year or upwards. There is also power in a magistrate2 to direct any person to allow his measurements or photographs to be taken for purposes of any investigation or proceeding under the Code of Criminal Procedure. Under section 73 of the Evidence Act, the court may direct any person present in court to give finger impressions or specimen handwriting for the purpose of comparison by the court.
1. Section 4, Identification of Prisoners Act, 1920.
2. Section 2, Identification of Prisoners Act, 1920.