What is the presumption under which intent is presumed in a criminal case?

Thus, the basis of the presumption involves a conclusion as to what would likely be in the mind of an ordinary person if he entered into such an agreement. In the absence of direct evidence of intent such as in The Queen v. O’Brien, it is difficult to imagine that a person could enter into an agreement to commit an indictable offence without a guilty intent; and the proof that the agreement was entered into must of itself be prima facie evidence of a guilty intention. I think that in cases of conspiracy the intent is so much a part of the agreement that it requires a separate consideration only when an accused tenders evidence to rebut the presumption. No such evidence was tendered here, no separate issue of intent was raised for the jury to consider, and in these circumstances I do not think it was error on the part of the learned Chief Justice to associate the intent with the agreement itself, as appears in the above passages from his charge. To me, the presumption makes them inextricable from each other unless the evidence raises an issue which requires them to be considered separately. If the agreement is proved, the intent is presumed: if it is not proved, no question of intent can arise.