There are a great many similar processes at the bottom of impressions that depend only upon swift and unconscious inference. Suppose, e.g., that I am shown the photograph of a small section of a garden, through which a team is passing. Although I observe the image of only a small portion of the garden and therefore have no notion of its extent, still, in speaking of it, I shall probably speak of a very big garden. I have inferred swiftly and unconsciously that in the fact that a wagon and horses were present in the pictured portion of the garden, is implied great width of road, for even gardens of average size do not have such wide roads as to admit wagons; the latter occurring only in parks and great gardens. Hence my conclusion: the garden must be very big. Such inferences[157] are frequent, whence the question as to the source and the probability of the witness’s information, whether it is positive or only an impression. Evidently such an impression may be correct. It will be correct often, inasmuch as impressions occur only when inferences have been made and tested repeatedly. But it is necessary in any case to review the sequence of inferences which led to this impression and to examine their correctness. Unfortunately the witness is rarely aware whether he has perceived or merely inferred. Examination is especially important when the impression has been made after the observation of a few marks or only a single one and not very essential one at that. In the example of the team the impression may have been attained by inference, but frequently it will have been attained through some unessential, purely personal, determinative characteristic. “Just as the ancient guest recognizes his friend by fitting halves of the ring, so we recognize the object and its constitution from one single characteristic, and hence the whole vision of it is vivified by that characteristic.”[158] All this is very well if no mistakes are made. When Tertullian said, “Credo quia impossibile est,” we will allow honesty of statement to this great scholar, especially as he was speaking about matters of religion, but when Socrates said of the works of Heraclitus the Obscure: “What I understand of it is good; I think that what I do not understand is also good”--he was not in earnest. Now the case of many people who are not as wise as Tertullian and Socrates is identical with theirs. Numerous examinations of witnesses made me think of Tertullian’s maxim, for the testimonies presented the most improbable things as facts. And when they even explained the most unintelligible things I thought: “And what you do not understand is also good.”