Consider the following scenario:
I am alone at home and I accidentally spill a bottle of ketchup on my kitchen floor, and the ketchup splatters across the floor in such a way as to form the words "Alex, you're a douchebag".
A superstitious person will view this as definitive evidence of some other-worldy forces trying to tell me something.
A rational person will conclude that someone managed, against all odds, to play some elaborate prank on me, as unlikely as it is that someone could ever rig the ketchup and the floor to form such a pattern.
Neither of them would for one second entertain the possibility that this was a pure coincidence. And yet it is still physically possible, all though the chances are infinitesimally small, that somehow the ketchup just happened to fall in exactly that pattern.
Why is this the case? Why would one be certain that some agency is involved?
I am trying to figure out the relationship with skepticism here: Why is radical skepticism acceptable in so many other epistemic scenarios (Does external reality exist? do other people have minds or are they just zombies? etc,...), but in this case we would be certain that it is not a coincidence, that some agent was behind the occurrence?
More over, I could be certain in real life that no matter how many times I spill Ketchup on the floor, I will never get the above mentioned pattern (unless some trickery is involved). What is the grounds for such certainty?
Although many of the answers have been instructive - a lot of them seem to responding to the fact that the pattern was a meaningful sentence. I realize that my example is misguiding. My question would still be the same if the ketchup fell in an orderly hexagonal lattice pattern, or a ying-yang symbol, or any pattern exhibiting unambiguous order. Most people would consider that such a pattern occurring by accident not just unlikely, but outright impossible in real life, even though such a splatter pattern is physically possible.
The issue is not just the explanation of why such a pattern occurred after the fact (i.e. if it happened, there must be an agent behind it). If someone were to perform the ketchup splatter experiment beforehand, they would tell you with absolute certainty that such an ordered pattern will never occur, even though it is physically possible. Why do we deem such an event impossible? Where does this certainty come from? We can be skeptical of everything, we can even doubt that the sun is going to come up tomorrow, or that the moon might fall out of the sky, but this is one thing we are certain of. It is not just a question of probabilities, since if someone were asked to bet on such an event occurring, they will laugh at the proposal, and yet people bet against astronomical odds all the time when playing the lottery.*