Academic Philosophy is a very broad field composed of five main subdisciplines which in turn divide into many dozens of sub-subdisciplines. The core fields, or subdisciplines, are:
Philosophy is a phenomena of the Axial Age and began in the 7th Century BCE in the Ionian region of Ancient Greece. It was marked by a rejection of the mythological world-view that had dominated human explanation until that time. The people we recognize as the earliest philosophers sought to give systematic, rational explanations of the world around them instead of the narrative accounts common to religion and epic poetry. The fundamental tension between muthos and logos (narrative and reason) can be summarized as follows: the mythological worldview holds the universe to be controlled by powers (i.e., ancestors, gods, spirits, etc.) beyond the limits of human knowledge. The rational worldview of philosophy begins with the supposition that the universe is knowable to humans and through careful observation and rational thought we can come to understand the world and our place in it.
The philosophers of the 7th and 6th Centuries BCE are referred to as Nature Philosophers as their primary interest was explaining the natural world around them. In the 5th Century Socrates of Athens was one of the first rational thinkers to turn attention to human nature in particular and made the study of human virtue a central phenomena of philosophical investigation.