A Chinese-American friend who tried to like the Sherlock Holmes books found himself continually frustrated that Holmes kept believing that the clues he discovered had only one possible explanation. Men of average height sometimes have the stride of a much shorter or taller man, he countered; ex-sailors might carry toys for two children as an errand for a shut-in neighbor. My friend is quite right.
As an example, I have walked in the woods more this past week, and we have had snow. I noted that some person with bigger feet than mine but probably lighter has been walking some of the same trails, coming in from Bog Rd. Large canine prints put down at about the same time suggest it is a taller man taking a big dog out for a walk/run. The doggie prints sometimes go away from the trail for 5 yards or 30, but always come back. I actually met them at the very end of my hike today, as they were coming in, and they look as imagined.
However, applying this same logic, I would have to conclude that another person of undetrmined sex (not indeterminate sex - don't get me in trouble here) comes in on snowshoes from New Boston, walking a pet deer. This seems unlikely, even in New Boston. But the deer prints are put down at about the same time, and they run together for over a mile in a loop. The deer tracks do go off to one side or another on occasion, but they come back to the trail soon, just as the dog's do. I thought I had established that the deer came later because its tracks printed over the human's. (Let's assume it was a human on the snowshoes. Let's not go completely overboard here.) Yet just a bit further on it was clear the snowshoe prints came after. I suppose that puzzle is solvable if we postulate that there are two deer, but surely, a man with two pet deer does not suddenly leave one on the trail, expecting that the other will appear shortly to complete his walk. That might do well for Tom Stoppard's solution in "Hapgood" to the Seven Bridges of Konigsburg problem, but This Is Reality, Greg.
This comes up in reference to Bible preachers who profess to be reliable because they tell you to bring your Bible along and look up what they are saying as they go along, to "prove" to you that they are not making this up and what they say can be relied on. I have come to conclude that this is a bad sign coming out of any preacher's mouth, and one had best be alert thereafter. I claim this is the real data and I tell you this is what it means. I insist you confirm for yourself that this is the real data. Therefore, you should believe me that this is what it means. The one does not follow from the other. The same goes for people trying to prove things to you in print or on internet - popular science and social science. The trick is very common. I say music is only a commodity in this society. Here! I have actual data that shows that people purchase sheet music and recorded performances. Some people make their livings on nothing else, and the entertainment industry permeates our entire economy. There! I've run rings around you logic'ly. Music is only a commodity in our society.
I think entire social sciences are founded on such things. Remember the person with the pet deer. Evidence can point in many directions and have many interpretations.