This was meant for the glossary but ended up too long. I'll link it from the glossary to this article. I just wanted to define it for those who may not understand a raise a few salient points.
I'll start with a brief definition of philosophy.
Philosophy- is the branch of study engaging in discussion, investigation, and development of abstract ideas and concepts by which man seeks to make sense of reality and the fabric of the universe. The etymology of the word itself means the love of wisdom.
Sometimes the term is used to refer to one's underlying principles guiding actions and interpretations. This is actually a sub-category dealt with below.
Christians are often exhorted to avoid philosophy. Not always bad advice, but there are certain reasons we should not be ignorant of it. I will give two.
Philosophy is engaged in a dialectical tension with theology. Traditionally philosophy has three main branches. These are:
Metaphysics, or discussions or categories 'beyond' the physical world or physics. Essentially we're talking about the spiritual world and even questions like time etc...
Epistemology, or study of knowledge. How do we know what we know? What is the nature of knowledge?
Ethics, or the behaviour and actions of man.
Immediately one should recognize these three categories are also theological. Theology proper is usually considered a branch of metaphysics. But I hope you can see one's theology will determine how one interprets other metaphysical questions, epistemology and ethics. But also how one answers questions concerning epistemology will determine one's ability to develop or not develop Theology. Epistemology shapes how we deal with Special Revelation, how we engage in metaphysics. What are the rules and guidelines, limitations, or lack thereof. How does logic come into play? What is logic itself? Like it or not, we employ it. It seems kind of crazy to do these things without ever giving it any thought.
Worldview is what flows out of these epistemological questions and answers concerning metaphysics. Ethics/action is the result of how we answer or fail to answer these other key questions. We all have a worldview, but I write elsewhere of the philosophical influences in Christian circles which has led to what is termed a Christian worldview, but I would argue is often far from it. How does this come about? How can we avoid wrong worldviews?
Philosophy and Theology are very much tied together in this dynamic tension. When engaging in Theology, we are dealing with philosophical questions. Philosophical questions are also theological.
If we don't consider some of the philosophical questions we run the risk of blindly developing our theology. As I've written on this site, philosophical presuppositions affect how we read the Bible. How ones answers certain underlying questions has a huge impact on Biblical hermeneutics.
Can philosophy help us in asking certain questions to help us develop a more full-orbed understanding of the issues as we interact with the Bible? Maybe. Sometimes. Other times it can lead us to ask the wrong questions. It requires some careful thought.
Like it or not, we are forced to deal with philosophical questions because we and everyone around us is putting some kind of philosophy into practice. It comes out in how people talk, act, and think.
By having some knowledge of what is out there, we can shield ourselves, interact and understand better, and understand how people and a culture have got to where they are, and where it all goes....
Do we need to sit around and read Kant and Hume in our spare time? No. In fact I will confess philosophy is nothing more than a dead end. Unbelievers can create elaborate and impressive systems but they all fail. Philosophy casts doubts, tears down, through sophistry assails truth. In the end, I usually end up in frustration wanting to wing the book across the room.
But Kant, Hume, and others have had a profound effect on how other people think, even if they've never read them. Perhaps growing up in 20th century America, Kant and Hume have affected us as well? How would we know unless we engage a little?
So, it's quite helpful and utterly worthless. But we can't escape the Theological-Philosophical Dialectic. We have to keep it in mind. Don't kill yourself reading Kant, but don't be afraid to wade into the discussion a little and familiarize yourself with the general concepts and ideas.