A fact assumed to be true under the law is called a presumption. For example, a criminal defendant is presumed to be innocent until the prosecuting attorney proves beyond a reasonable doubt that she is guilty. Presumptions are used to relieve a party from having to actually prove the truth of the fact being presumed. Once a presumption is relied on by one party, however, the other party is normally allowed to offer evidence to disprove (rebut) the presumption. The presumption is known as a rebuttable presumption. In essence, then, what a presumption really does is place the obligation of presenting evidence concerning a particular fact on a particular party.
An inference as to the existence of one fact, from the existence of some other fact, founded on a previous experience of their connexion. Or it, is an opinion, which circumstances, give rise to, relative to a matter of fact, which they are supposed to attend.
To constitute such a presumption, a previous experience of the connection between the known and inferred facts is essential, of such a nature that as soon as the existence of the one is established, admitted or assumed, an inference as to the existence of the other arises, independently of any reasoning upon the subject. It follows that an inference may be certain or not certain, but merely, probable, and therefore capable of being rebutted by contrary proof.In general a presumption is more or less strong according as the fact presumed is a necessary, usual or infrequent consequence of the fact or facts seen, known, or proven. When the fact inferred is the necessary consequence of the fact or facts known, the presumption amounts to a proof when it is the usual, but not invariable consequence, the presumption is weak; but when it is sometimes, although rarely,the consequence of the fact or facts known, the presumption is of no weight.
Presumptions are either legal and artificial, or natural.
Legal or artificial presumptions are such as derive from the law a technical or artificial, operation and effect, beyond their mere natural. tendency to produce belief, and operate uniformly, without applying the process of reasoning on which they are founded, to the circumstances of the particular case. For instance, at the expiration of twenty years, without payment of interest on a bond, or other acknowledgment of its existence, satisfaction is to be presumed; but if a single day less than twenty years has elapsed, the presumption of satisfaction from mere lapse of time, does not arise; this is evidently an artificial and arbitrary distinction. An example of another nature is given under this head by the civilians. If a mother and her infant at the breast perish in the same conflagration, the law presumes that the mother survived, and that the infant perished first, on account of its weakness, and on this ground the succession belongs to the heirs of the mother.
Legal presumptions are of two kinds: first, such as are made by the law itself, or presumptions of mere law; secondly, such as are to be made by a jury, or presumptions of law and fact.
Presumptions of mere law, are either absolute and conclusive; as, for instance, the presumption of law that a bond or other specialty was executed upon a good consideration, cannot be rebutted by evidence, so long as the instrument is not impeached for fraud or they are not absolute, and may be rebutted evidence; for example, the law presumes that a bill of exchange was accepted on a good consideration, but that presumption may be rebutted by proof to the contrary.
Presumptions of law and fact are such artificial presumptions as are recognized aud warranted by the law as the pro er inferences to be made by juries under particular circumstances; for instance, au unqualified refusal to deliver up the goods on demand made by the owner, does not fall within any definition of a conversion, but inasmuch as the detention is attended with all the evils of a conversion to the owner, the law makes it, in its effects and consequences, equivalent to a conversion, by directing or advising the jury to infer a conversion from the facts of demand and refusal.
Natural presumptions depend upon their own form and efficacy in generating belief or conviction on the mind, as derived from these connexions which are pointed out by experience; they are wholly independent of any artificial connexions and relations, and differ from mere presumptions of law in this essential respect, that those depend, or rather are a branch of the particular system of jurisprudence to which they belong; but mere natural presumptions are derived wholly by means of the common experience of mankind, from the course of nature and the ordinary habits of society.