Learner's definition of PHILOSOPHY
1 a [noncount] : the study of ideas about knowledge, truth, the nature and meaning of life, etc. — often used before another noun b [count] : a particular set of ideas about knowledge, truth, the nature and meaning of life, etc. — often + of 2 [count] : a set of ideas about how to do something or how to live
Her main cooking philosophy is to use only fresh ingredients.
My philosophy is to live and let live. [=let other people live the way they want to]
His philosophy of life [=his way of living] is to treat people as he would like to be treated.