Section 45 BSA: Grounds of Opinion, When Relevant

Section 45 BSA makes the reasons and supporting material behind a relevant opinion admissible for consideration by the court.

Introduction

Section 45 of the Bharatiya Sakshya Adhiniyam, 2023 (BSA) explains why the grounds on which a relevant opinion is based also matter in judicial proceedings. A court should not merely hear an opinion; it must be able to examine the basis on which that opinion was formed.

For example, when an expert gives an opinion based on scientific testing, the expert may also explain the experiments performed to reach that conclusion. The court can then assess whether the opinion is supported by a sound foundation.

Section 45 does not make every opinion relevant. It applies when the opinion is already relevant under the applicable law. The section then makes the grounds supporting that opinion relevant as well.

This provision corresponds to Section 51 of the Indian Evidence Act, 1872.

Bare Act: Section 45 of the Bharatiya Sakshya Adhiniyam, 2023

45. Grounds of opinion, when relevant.—

Whenever the opinion of any living person is relevant, the grounds on which such opinion is based are also relevant.

Illustration.

An expert may give an account of experiments performed by him for the purpose of forming his opinion.

Also Read: Section 13 of Bharatiya Sakshya Adhiniyam, 2023: Facts Bearing on Whether an Act Was Accidental or Intentional

Meaning of Section 45 BSA

Section 45 establishes a straightforward evidentiary principle: when an opinion is relevant, the reasons and material supporting that opinion are also relevant.

The provision helps the court evaluate the reliability and evidentiary value of an opinion. The court may examine the observations, experiments, data, reasoning or other relevant material on which the person relied.

For example, if a forensic expert concludes that a substance contains a particular chemical, the expert may explain the tests conducted, the observations recorded and the reasoning connecting the results to the conclusion. These grounds help the court assess the opinion rather than accepting it without scrutiny.

The section is not limited to scientific experts. Its language refers to the opinion of any living person, provided that the opinion itself is relevant under the law of evidence.

Essential Elements of Section 45 BSA

1. The opinion must be relevant

The section operates only when the opinion of a person is relevant under another applicable provision or legal rule.

For example, Section 39 BSA deals with expert opinions on specified matters, while Sections 41 to 44 deal with particular kinds of opinions, including handwriting, customs, usages and relationships.

Section 45 complements these provisions by making the grounds of a relevant opinion relevant too.

2. The grounds supporting the opinion are relevant

The word “grounds” refers to the basis on which the opinion was formed. Depending on the circumstances, this may include observations, experiments, tests, data, comparisons, documents or reasoning.

The material must have a connection with the opinion in question. Section 45 does not make every fact known to the person relevant merely because that person has expressed an opinion.

Also Read: Section 11 of Bharatiya Sakshya Adhiniyam, 2023: Facts Relevant When Right or Custom Is in Question

3. The court can examine how the opinion was formed

The provision enables the court to assess the foundation of an opinion. An opinion based on reliable observations and properly conducted tests may carry different weight from one based on incomplete information or an unsupported assumption.

The section does not prescribe a fixed formula for weighing every opinion. The court evaluates the evidence in the context of the case.

4. Relevance does not mean conclusive proof

The fact that the grounds of an opinion are relevant does not mean that the opinion must be accepted as correct.

The court may consider whether the grounds are reliable, whether the reasoning is persuasive, whether contrary evidence exists and whether the opinion withstands cross-examination.

Illustration Explained: An Expert’s Experiments

Section 45 provides one illustration: an expert may give an account of experiments performed for the purpose of forming an opinion.

Example

Suppose a forensic expert examines a substance recovered during an investigation and concludes that it contains a particular chemical.

The expert may explain:

• The procedure followed during the examination.
• The tests or experiments performed.
• The observations and results obtained.
• The scientific reasoning used to reach the conclusion.
• Any relevant limitations affecting the interpretation of the results.

These details help the court evaluate the expert’s opinion and determine the weight it deserves.

The illustration does not mean that conducting an experiment automatically makes an expert’s conclusion correct. The reliability of the methods, the quality of the observations and the reasoning behind the conclusion remain matters for judicial assessment.