Intent. In proving Intent, the act is conceded or assumed what is sought is the state of mind that accompanied it. In proving Design, the act is still undetermined, and the proof is of a working plan, operating towards the future with such force as to render probable both the act and the accompanying state of mind. The Intent is a mere appendage of the act; the Design is force producing the act as a result " (Law of Evidence, 2nd. ed. (1923), vol. 1, p. 609). From this distinction, it would appear to follow that evidence to show intent need not necessarily reveal any feature of common purpose or general scheme as a necessary requirement of admissibility. Thus Wigmore says :-
It is not here necessary to look for a general scheme or to discover a united system in all the acts; the attempt is merely to discover the intent accompany- ing the act in question and the prior doing of other similar acts, whether clearly a part of a scheme or not, is useful as reducing the possibility that the act in question was done with innocent intent. The argument is based purely on the doctrine of chances, and it is the mere repetition of instances and not their system or scheme, that satisfies our logical demand. Yet, in order to satisfy this demand, it is at least necessary that prior acts should be similar. Since it is the improbability of a like result being repeated by mere chance that carries probative weight, the essence of this probative effect is the similarity of the instance" (ibid., p. 615). Accordingly, upon the issue of intent, a precise resemblance between the various instances is unnecessary. Upon such issue, therefore, the evidence in R. v. Armstrong 1 and R. v. Hall 2 was receivable.
Moreover, the strength of the inference does not rest exclusively on a given person's connection with the other transactions, for it is possible " to infer deliberate human intent without forming any conclusion as to the personality of the doer" (Wigmore, vol. 1, p. 616). Where, however, the very doing of the act is still to be proved, one of the evidential facts receivable is the person's Design
(ibid., p. 617). The object here, says Wigmore, is not merely to negative an innocent intent at the time of the act charged but to prove a pre-existing design, system, plan or scheme, directed forwards to the doing of that act. In the former case (of Intent) the attempt is merely to negative the innocent state of mind at the time of the act charged in the present case the effort is to establish a definite prior design or system, which included the doing of the act charged as a part of its consummation. In the former case, the result is to give a complexion to a conceded act, and ends with that in the present case, the result is to show (by probability)
1(1922) 2 K.B. 555.
2(1887) 5 N.Z.L.R. 93.