Below are some of my most admired philosophers. I have included what I feel their field of expertise is in brackets.
Alan Watts (Lifestyle, Self Awareness)

Lou Tzu (Lifestyle, Self Awareness)

Gautama Buddha (Lifestyle, Self Awareness)

Mooji (Lifestyle, Self Awareness)

Eckhart Tolle (Lifestyle, Self Awareness)

Jiddu Krishnamurti (Lifestyle, Self Awareness)

Thich Nhat Hanh (Lifestyle, Self Awareness)

Wayne Dyer (Lifestyle, Self Awareness)

Jesus Christ (Lifestyle, Leadership, Self Awareness); non religious purposes

Bruce Lee (Lifesyle, Self Awareness, Sport)

Tony Robbins (Lifestyle, Business, Wealth, Peak Performance, Sport, Relationships)

Oprah (Lifestyle, Self Awareness, Relationships)

Dr.Phil (Lifestyle, Relationships)

Eben Pagan (Business, Relationships)
