And with all respect to 5go’s post, while it may seem that JWs are more logical about their religion than Catholics, that may be just a point of view, based on how one looks at things.
Remember that JWs base their belief on the Bible. Catholicism is not based on the Bible. It is based on the founders of that faith’s encounter with Jesus of Nazareth, and what they believed the events surrounding his life meant; and they see the Bible as based on their religion.
Whereas the Witnesses point to the Bible as the authority for their beliefs, you have to remember that Catholicism did not have such a luxury as the New Testament was yet to be composed, gathered, distributed, etc. Catholicism developed out of an oral tradition that was passed on and eventually written down, some writings which Catholics claim make up the current New Testament.
The Witnesses view the Bible as a book telling people what they should believe, defining all doctrine. Catholics view the Bible as a witness to the truth of its doctrines, but not an exhaustive reference of them all or a treatise on Christian doctrine—they were already an operating religion with many facets by the time it was composed and canonized.
With respect to those who hold to the sola scriptura view, the Witnesses may indeed seem more logical. From the point of view of those who see some value in the way Catholicism developed, the Witnesses don’t make much sense at all.
Regardless of which school of thought you favor, however (and each person’s view should be respected, I believe), I think a religion that makes constant prophetic promises and changes its doctrines so drastically when they don’t come true—smashing many people’s lives in the process—is not the touchstone of what should be considered logical.