Often times we find that great thinkers disagree on fundamental issues. Have you ever wondered why? We are all prone to logical errors! We were given the capacity to reason, but are far from perfect in our reasoning ability. We've been known to make illegitimate inferences and commit errors that violate the laws of logic. These are most commonly noted in political or religious debates.
Empirical errors is one of the reasons for off base opinions.
Everyone of us is limited in the scope of our experience and perspective. No one has been capable of surveying all of the data needed to come to a logical conclusion; ergo we take shortcuts and arrogantly make assumptions based on our senses. The limitations of our sense perception adds greatly to making mistakes. Perception is not always reality! A great example is when we go to a doctor for a second opinion.
We will make errors of interpretation as a result of clouded thinking.
Sometimes we allow ourselves to be bias against the data, because it doesn't align with our world view. This is why it's critical to know what we believe, and be able to defend why we believe it. Where are your opinions formed? Are they based on the studies of classical literature, and the experiences of the great scholars who've written in history, or are they parroted regurgitation, mindlessly blathered without substance?