The Roman philosopher Cicero believed that in order to have a true friendship with someone, one must have complete honesty, truth, and trust. He also thought that friends would do things for each other without expectation of repayment. If a friend is about to do something wrong, one should not compromise one's morals and let the friend commit the action--one should explain what is wrong about the action, and help one's friend understand what is right. Cicero believed that ignorance is the cause of evil.
To me the defintion of a best friend is when a friend knows all of your faults, your failures, your accomplisments, your goals, your entire you because you felt confortable sharing it, has been there for you when you were down and celebrated with you when you were happy, and someone that you can count on no matter what. A best friend is someone you want to call to talk about a bad day, call to celebrate something great that happened in your life and someone who loves you for just being you.
To me, my best friend is my husband. I love him and trust him with my life. Although I do consider VERY FEW others close friends, I know my husband will always be the one I can count on, no matter what. He is the love of my life as well as my best friend and that to me is the best combination.