The court decided that the only rational conclusion from this evidence was that the recording was done for a sexual purpose. (mydefence.ca)
And from there you can made rational conclusions of WHO built them if indeed there is a WHO. (religion.blogs.cnn.com)
We can come to scientific and rational conclusions as to the optimum number of people based on the quality of life we would like to ensure. (dotearth.blogs.nytimes.com)