answer:Yes, there must be a limit. First, assume that there is a finite amount of matter in the world. If there is a finite amount of matter, then there is also a finite (even if vastly large) number of ways in which it can be arranged. Thus there is necessarily a finite number of possible anythings. Not all possible arrangements of matter will count as a human face, however, so an even smaller finite number will express the limit of how many human faces there can be. But what if there is not a finite amount of matter? In that case, it will still be the case that only certain arrangements will count as a human face. Nothing too large will count, and neither will something too small. It is the former point that matters to us, though: if there is an upper limit on the size a human face, then there is an upper limit on the amount of matter that there can be in a human face. Thus we are left with the solution given in the previous paragraph: given that there is a finite limit on the amount of matter that can be in a human face, there is a finite number of ways in which it can be arranged and an even smaller finite number of ways it can be arranged that will count as a human face. Conclusion: regardless of whether there is a finite or infinite amount of matter in the world, there is a finite limit to the number of human faces possible.