Here is my thought for the day: You can generally judge the depth of a thinker and the value of his/her thoughts by how familiar s/he is with the thoughts of others.
There is a difference between a person who has formed ideas, and a person who has formed ideas in the context of other thinkers’ ideas. Generally speaking, those who are ignorant of the insights and developments of others in the past and present, have a very limited, and often skewed perspective. They are likely to miss the big picture, repeat the mistakes of others in the past, or fail to account for something simply because they have yet to consider it.
Those who form their thoughts in a vacuum from other thinkers tend toward error. I often hear preachers preface some remark by saying, “I didn’t get this from no man. The Lord revealed to me straight from the Good Book.” Whenever I hear that, I know chances are that what I’m about to hear is probably off-base. And it usually is. As Charles Spurgeon said, “It seems odd, that certain men who talk so much of what the Holy Spirit reveals to themselves, should think so little of what he has revealed to others.” Those who try to reinvent the wheel without knowledge of past wheel makers, never do a very good job at it.
Those who have conversed with the thinkers of today and yesteryear, however, will tend to have a much better, more informed perspective. They tend to be more balanced, and aware of their intellectual limitations. When I read something someone wrote on the topic of theology or philosophy, I’m looking at the footnotes to see what sources, if any, the author has used. It’s usually a good indication of the quality of work I’m about to read.
When it comes to theology and philosophy, we would be stupid not to pay attention to what others have said before us. It is the epitome of hubris to think others (particularly those in the past) have little or nothing to offer us. 99.99% of what we know is inherited from the intellectual labor of those who came before us. If we ignore them, we are only left with 0.01% of true knowledge. Woe to us if we attempt to think in an intellectual vacuum.