Locke saw a bright light from the Smoke Monster scanning him and thought that was beautiful. Mr. Eko saw only the dark smoke. Ben saw images from his past, so maybe Mr. Eko also saw dark scenes like that? In any case Locke was deceived as Jack was by Smokey. Smokey claimed he wanted Jack to find water, but he really wanted Jack to kill himself falling off a cliff so there'd be one less candidate who cared about other people. Once they established the time loop, then almost everything had to happen the way it happened to prevent paradox (though the compass became a paradox). Thus the answer to every "what if?" became, "It couldn't have happened that way." No free will makes for bad stories.
