Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense.
This is a bad translation of the Kalama Sutta — so bad, in fact, that it contradicts the message of the sutta, which says that reason and common sense are not sufficient for ascertaining the truth.
And it’s very common as well.
Here’s the original version, from Access to Insight:
“Now, Kalamas, don’t go by reports, by legends, by traditions, by scripture, by logical conjecture, by inference, by analogies, by agreement through pondering views, by probability, or by the thought, ‘This contemplative is our teacher.’ When you know for yourselves that, ‘These qualities are skillful; these qualities are blameless; these qualities are praised by the wise; these qualities, when adopted & carried out, lead to welfare & to happiness’ — then you should enter & remain in them.
The Buddha is talking to some people who live near his home country. These people, the Kalamas, are confused by the multiplicity of teachings that they hear. Many teachers arrive, who extoll their own teachings and disparage the teachings of others. And the Kalamas want to know, “Which of these venerable brahmans and contemplatives are speaking the truth, and which ones are lying?”
The Buddha’s reply is very full, but it’s clear he says that “reason” (logical conjecture, inference, analogies, agreement through pondering views) and “common sense” (probability) are not sufficient bases for determining what the truth is. It’s not that these things should be discarded, but ultimately it’s experience and the opinion of the wise that is our guide.
So this brings up at least two questions:
1. If experience is to be our guide, does that mean we have to test out every theory and practice? No. If a teacher says something like “taking drugs is the path to happiness” you don’t have to try drugs. Your experience includes observation of other people’s experience, so that if you have seen others suffering through taking drugs you don’t have to repeat their mistakes.
2. Who is to say who the wise are? You are. Through your experience (see point 1, above), whom have you found to be reliable and insightful in the past? Those people are “the wise”. Now you don’t have to take everything they say as being the absolute truth. You can use your reason, your common sense, and your experience as a guide. Not all of “the wise” will agree, for example, so you’re still going to have to figure things out for yourself ultimately.
It’s this second criterion that is often overlooked.
The first instance of this version of the quote that I’ve found is in a libertarian book by the pseudonymous author, “John Galt” — Dreams Come Due. I strongly suspect that Galt’s libertarianism caused him to alter the quote in order to make it supportive of his position.
Incidentally, the “no matter where you read it” is an anachronism, since spiritual teachings were orally transmitted at the time of the Buddha.