Knowing in yourself

Do not be satisfied with hearsay or with tradition or with legendary love or with what has come down in scriptures or with conjecture or with logical inference or with weighing evidence or with liking for a view after pondering over it or with someone else´s ability or with the thought "The monk is our teacher." When you know in yourselves: "These things are wholesome, blameless, commended by the wise, and being adopted and put into effect they lead to welfare and happiness," then you should practice and abide in them ...

The Buddha, Kalama Sutta (quoted from Buddhism Without Beliefs, 1)