Report No. 69
Opinion Evidence-Other Provisions
*. The paras have not been numbered in this Chapter, in the Report published by the Law Commission.
Section 46.-We have disposed of the important questions relating to opinion evidence. We shall deal in this chapter with certain other provisions as to opinion evidence. The first such provision is contained in section 46. Facts, not otherwise relevant, are relevant under section 46, if they support or are inconsistent with the opinions of experts, when such opinions are relevant.
The illustrations to the section are as follows:-
"(a) The question is, whether A was poisoned by that poison.
The fact that other persons, who were poisoned by that poison, exhibited certain symptoms which experts affirm or deny to be the symptoms of that person, is relevant.
(b) The question is, whether an obstruction to a harbour is caused by a certain sea-wall.
The fact that other harbours similarly situated in other respects, but where there were no such sea-walls, began to be obstructed at about the same time, is relevant."
Section 46-Principle.-The principle underlying section 46 could be better understood, if some of the, reasons for admitting expert evidence are recalled.
(1) The use of witnesses being to inform the tribunal respecting facts, their opinions are not, in general, receivable as evidence.
(2) The rule, however, is not without its exceptions. The rule is based on the presumption that the tribunal is as capable of forming a judgment on the facts as the witnesses. When circumstances rebut this presumption, the rule naturally gives way, and the opinions of specially skilled persons are receivable in evidence.1
(3) Now, the foundation on which expert testimony rests is the supposed superior knowledge or experience of the expert in relation to the subject-matter upon which he is permitted to give an opinion as evidence.
(4) The opinion of such person gains weight if the supporting circumstances are proved. The reverse is also true.
That is the rationale of section 46, and we do not think that the section needs any change.
1. Best Evidence, paras. 511-513.
The sections which we have so far discussed embrace a variety of matters on which opinion evidence can be given. Certain particular matters appeared to the draftsman of the Act to deserve special treatment in regard to opinion evidence. these are dealt with in section 47 et seq. Section 47 provides that when the Court has to form an opinion as to the person by whom any document was written or signed, the opinion of any person acquainted with the hand-writing of the person by whom it is supposed to be written or signed that it was or was not written or signed by the person a is relevant fact.
Under the Explanation to section 47, a person is said to be acquainted with the handwriting of another person when he has seen that person write, or when he has received documents purporting to be written by that person in answer to documents written by himself or under his authority and addressed to that person or when, in the ordinary course of business, documents purporting to be written by that person have been habitually submitted to him. These various facets are illustrated by the illustration to the section, which-reads
"The question is, whether a given letter is in the hand-writing of A, merchant in London.
B is a merchant in Calcutta, who has written letters addressed to A and received letters purporting to be written by him. C is B's clerk, whose duty it was to examine and file B's correspondence. D is B's broker, to whom I habitually submitted the letters purporting to be written by A for the purpose of advising with him thereon. The opinions of B, C and D on the question whether the letter is in the, handwriting of A are relevant, though neither B, C nor D ever saw A write.
Section 47-principle of comparison.-The principle underlying the section is th.- the opinion or the belief of a witness is admissible, because all proof of handwriting, except when the witness either wrote the document himself, or said it written, is, in its nature, comparison. It is the belief which a witness entertains upon comparing the writing in question with an example formed in his mind from some previous1knowledge, which is the basis of his evidence.
Change not needed.-Viewed in this light, the section is intelligible enough, an needs no change.
1. Taylor Evidence, para. 1869, cited in Woodroffe.