86 HARVARD LAW REVIEW. As regards the proof of execution, where the document is attested, the rule runs back to the most ancient periods of our law. The document witnesses were formerly summoned with the jury, and joined in their secret deliberations.^ This was done until about four centuries ago, and perhaps later. From these older periods there survived a rigor of requirement as to summoning the attesting witnesses, and a precedence in that method of proving the execution over all others, which have long been irrational ; the law is still encumbered with many troublesome remnants of the old doctrine and many ill-instructed decisions. As regards the proof of alterations in documents the cases are full of confusion. Fragments of substantive law embarrass the rules of evidence relating to this subject; and it is further intoler- ably perplexed by the introduction of a quantity of jargon about presumptions and the burden of proof, which often conceals the lack of any clear apprehension of the subject on the part of those who use it, and often disguises the true character of sound decisions. Such is a rough outline of the chief characteristics of our law of evidence. Speaking exactly, this part of the law deals merely with the business of furnishing to the tribunal such information as to matters of fact in issue as is needed in order to decide the dis- pute, or to make any desired order. It assumes a properly quali- fied tribunal, one that knows an evidential thing when it sees it. It does not re-enact, nor does it displace, the main rules which govern human thought. These are all taken for granted. But it does exclude, by rules, much which is logically probative. It also regulates the production of witnesses, and documents, and visible objects offered for inspection as the basis of inference. The chief defects in this body of law, as it now stands, are that motley and undiscriminated character of its contents which has been already commented on ; the ambiguity of its terminology ; the multiplicity and rigor of its rules and its exceptions to rules; the difficulty of grasping these and of perceiving their true place and relation in the system ; and of determining, in the decision of new questions, whether to give scope and extension to the rational principles that lie at the bottom of all modern systems of evidence, or to those checks and qualifications of these principles which have 1 Thayer, Prelim. Treatise on Ev. 97.
