 Since we’ve canvassed the leading contenders for the source of our idea of necessary connection and found them wanting, it might seem as if we have no such idea, but that would be too hasty. In our discussion of causal inference, we saw that when we find that one kind of event is constantly conjoined with another, we begin to expect the one to occur when the other does. We suppose there’s some connection between them, and don’t hesitate to call the first, the cause, and the second, the effect. We also saw that there’s nothing different in the repetition of constantly conjoined cases from the exactly similar single case, except that after we’ve experienced their constant conjunction, habit determines us to expect the effect when the cause occurs.