I would like to share some parallels I have seen between the Kalama Sutta and Philosophical scepticism, specifically Pyrrhonist scepticism.
Pyrrhonist scepticism was (supposedly) founded by Pyrrho, a contemporary of Alexander the Great and who apparently accompanied him in his conquest of India, and conversed with "naked philosophers" of India. This school of scepticism we know mostly from the works of Sextus Empiricus. In this school of thought, a person is said to find peace who "withholds assent to non-evident propositions". That is to say, a sceptic can say "X appears thus" but cannot say that X appears thus to everyone else, neither can he say what X is truly like. He can only say that "X appears thus" to me, in this moment. Therefore they withhold assent to propositions, achieve indifference (equanimity) and achieve Ataraxia, or peace of mind
N.B. Ataraxia (ἀταραξία "tranquility") is a Greek term used by Pyrrho and Epicurus for a lucid state of robust tranquillity, characterized by ongoing freedom from distress and worry.CHAPTER X. – DO THE SCEPTICS ABOLISH APPEARANCES?
Those who say that "the Sceptics abolish appearances," or phenomena, seem to me to be unacquainted with the statements of our School. For, as we said above, we do not overthrow the affective sense-impressions which induce our assent involuntarily; and these impressions are "the appearances." And when we question whether the underlying object is such as it appears, we grant the fact that it appears, and our doubt does not concern the appearance itself but the account given of that appearance, -- and that is a different thing from questioning the appearance itself.
For example, honey appears to us to be sweet (and this we grant, for we perceive sweetness through the senses), but whether it is also sweet in its essence is for us a matter of doubt, since this is not an appearance but a judgement regarding the appearance. And even if we do actually argue against the appearances, we do not propound such arguments with the intention of abolishing appearances, but by way of pointing out the rashness of the Dogmatists; for if reason is such a trickster as to all but snatch away the appearances from under our very eyes, surely we should view it with suspicion in the case of things non-evident so as not to display rashness by following it.http://evans-experientialism.freewebspa ... icus02.htm
Now in the Kalama Sutta the Buddha teachesThe criterion for acceptance
10. "Come, Kalamas. Do not go upon what has been acquired by repeated hearing; nor upon tradition; nor upon rumor; nor upon what is in a scripture; nor upon surmise; nor upon an axiom; nor upon specious reasoning; nor upon a bias towards a notion that has been pondered over; nor upon another's seeming ability; nor upon the consideration, 'The monk is our teacher.' Kalamas, when you yourselves know: 'These things are good; these things are not blamable; these things are praised by the wise; undertaken and observed, these things lead to benefit and happiness,' enter on and abide in them.http://www.accesstoinsight.org/lib/auth ... el008.html
Now the Buddha is saying something similar, possibly even the same thing, as Sextus. He is saying that one cannot go on "tradition, authority, reasoning" etc and should withhold assent to these non evident propositions.
Only by experiencing that which is apparent
to us, can we arrive at peace and leave the philosophical "thicket of views" behind.
When we do this we achieve Ataraxia, or a nibbana, in relation to views and opinions, I.e. in relation to that which is not apparent
However I would say there is a possible difference in the two approaches. Sextus appears to reach this via reasoning, the Buddha via detached observation.