I missed your comment. I found it now. I will reply there.

http://lesswrong.com/lw/3ox/bayesianism_versus_critical_rationalism/3uld?context=1#3uld

could we say that support for a proposition is logically equivalent to a criticism of its negation?

No. The negation of a universal theory is not universal, and the negation of an explanatory theory is not explanatory. So, the interesting theories would still be criticism only, and the uninteresting ones (e.g. "there is a cat") support only. And the meaning of "support" is rather circumscribed there.

If you want to say theories of the type "the following explanation isn't true: ...." get "supported" it doesn't contribute anything useful to epistemology. the support idea, as it is normally conceived, is still wrong, and this rescues none of the substance.

The other issue is that criticism isn't the same kind of thing as support. It's not in the same category of concept.

Yes I really reject the policeman's syllogism. In the sense of: I don't think the argument in the book is any good. There are other arguments which are OK for reaching the conclusion (but which rely on things the book left unstated, e.g. background knowledge and context. Without adding anything at all, no cultural biases or assumptions or hidden claims, and even doing our best to not use the biases and assumptions built into the English language, then no there isn't any way to guess what's more likely).