I love fish, just about any kind. That is why, as a young Believer, when I was told by a preacher who was also an avid fisherman how to read my Bible, I understood his homespun metaphor. He said, when reading the scripture and coming to a text I don't understand, it's like eating fish. When you come to a bone, you don't stop, but simply lay the bone aside and keep eating. Through the years, I've found this to be advantageous, in both eating fish and reading my Bible. Their is much more meat, in both cases, than bones.
This can also be applied to secular and religious reading. We can forfeit a lot of knowledge by neglecting writers who do not cross all their "T's," and dot all their "I's," as we would like. Most certainly, it is important to read such books discretionally, but read them we must. That is, unless we choose to spend all our lives presenting a stubborn narrow-minded individual to others. Such people are not difficult to recognize; they wear a bright colored dunce's cap that all can see. They are ignorantly proud of their self-imposed intellectual limitations.
Many of my readers were, or are, associated with some elitist group that discourages the reading of any literature other than what is produced or approved by them. I like a line in the dedicatory of the 1611 King James Bible which describes this type as "...self-conceited Brethren, who run their own ways, and give liking unto nothing, but what is framed by themselves, and hammered on their anvil."
I find great solace in the fact that possibly the greatest Spiritual mind that ever graced this earth, Paul the Apostle, read after the poets of his day, and was familiar with the teachings of science. I would think from this "the books" Paul asked Timothy to bring to him while in prison included both secular and spiritual.