Philosophy is "the study of the most general and abstract features of the world and categories with which we think: mind, matter, reason, proof, truth etc. In philosophy, the concepts by which we approach the world themselves become the topic of enquiry."

The definition is self explanatory.

The Root :
Thinking ( Ability to think )

Tools :

1. reason
2. mind
3. intuition
4. mind set
5. database of knowledge
   
6. -- will add as soon as I get across one --

Need :
Based on our philosophy we can be lead to actually two contrasting ends.Right or wrong is subjective.What maybe right for me can actually be a wrong for you.Its here that the philosophy concept comes with its added advantages: it can very well serve as a shining light in a dark tunnel of inexperience and difficulty.

Result:
If not followed properly the social contacts can deplete rapidly, there will be no one who will believe in you and there are fairly good chances that you can be called a buffon and a fool.
If followed properly then too all these things apply.

Reason to follow:
If "nothing else matters" is your mantra and tantra of life then its ideal for you.After your death and another 200 years there might be a possibilty that people will start understanding your deductions and thoughts.

just like that