1. Conclusive proof:
It consists of evidential facts of such probative force that they are not capable of being contradicted. When one fact is declared by law to be conclusive proof of another, the court shall, on proof of one fact, regard the other as proved, and shall not allow evidence to be given for the purpose of disproving it. Conclusive presumptions are inferences which the law makes so peremptorily that it will now allow them to be overturned by any contrary proof however strong.
Section 112 of the Indian Evidence Act lays down that if a person is born during a valid marriage between his mother and any man, or within 280 days after its dissolution, the mother remaining unmarried, then, unless non-access is proved, it shall be a conclusive proof of his legitimacy.
2. Presumptive or conditional proof:
It consists of facts which amount to proof only so long as they are not contradicted. It raises a rebuttable presumption, which may be proved to be wrong by contrary evidence.
Thus, a man not heard of for seven years by those who would naturally have heard of him, if he had been alive, is presumed to be dead.
This presumption, however, can be rebutted by contrary proof. In other words, unlike conclusive proof in the case of presumptive proof of the court will permit contrary evidence to disprove a fact.
3. Insufficient evidence:
Where the law prescribes a certain quantity of evidence, nothing short of that evidence will be regarded as amounting to proof. A will requires attestation by two witnesses. Nothing short of it will be sufficient to enable the courts to take cognizance of the will.
4. Exclusive evidence:
Certain facts alone are recognised as being the only evidence of certain other facts, and no other evidence however credible will be admissible as evidence.
Thus, the execution of a will can be proved only by the testimony of one attesting witness, unless, owing to death, such testimony is not available.
Then, whenever any public or private document has been reduced to a documentary form, the document in which it is recorded becomes exclusive evidence of that transaction.
5. Facts which are not evidence:
There are certain facts which are destitute of any probative force and the courts take no cognizance of such non-essential facts. Hearsay evidence, which does not derive its credit from the witness himself but rests on the competency of some other person, is no evidence.
Certain witnesses cannot be compelled to disclose certain facts and the law excludes the same on the ground of public policy under sections 121 to 126 of the Indian Evidence Act. The rules are as under:
1. Judge and Magistrate:
A judge or magistrate cannot be compelled to answer any question as to his conduct or as to anything which comes to his knowledge as such except on the special order of some courts to which he is subordinate.
2. Communication during marriage:
A person cannot be compelled to disclose any communication made to him or her during marriage by any person to whom he or she has been married.
3. Affairs of the State:
No person can give evidence from unpublished records relating to the affairs of the Stale except with the permission of the head of the department concerned.
4. Official Communication:
No public officer can be compelled to disclose communications made in official confidence, if public interest would suffer by the disclosure.
5. Information as to crime:
A magistrate or public officer cannot be compelled to say from where he got any information as to the commission of an offence.
6. Professional communication:
An advocate or pleader cannot be compelled to disclose, without the client’s consent, any communications made to him in the course of, and for the purpose of, the employment, the contents or condition of any document with which he became acquainted during the course of his employment and any advice by him to his client.
Besides these, no person not even an accused can be compelled to answer any question that may tend to incriminate him, person may make a confession as to the commission of a crime, but should be free and voluntary and then only it can be received at evidence. A confession is irrelevant if it is obtained by inducement threat or promise.