Dogen can't (or won't) lie by The Graphite

It seems to me that Dogen either cannot or will not lie. (I'm inclined to believe the latter, as I'll explain below.)

There's been much conjecture about whether Sayid could have really killed FLocke if Sayid had stabbed him before Locke spoke. I believe now that Dogen was speaking the truth.

Consider that Dogen has been willing to use subterfuge to accomplish what he believes is right or necessary, such as giving Jack the poison pill for Sayid. Dogen cannot kill Sayid, himself. This seems obvious. Why? Because candidates can only be killed by other candidates, which is why Dogen required JACK to give the pill to Sayid. Sayid can't kill himself, either, which is why Dogen intended for Jack to give the pill to Sayid without telling him what was in the pill. Thus, Jack would have killed Sayid in that case - something Dogen could not do.

(On a side note, I think this also indicates that when Dogen attacked Sayid, he was doing so to restrain him, not kill him. I did not see Dogen execute any potentially lethal moves against Sayid, such as running him through with a knife, etc. He wanted to subdue Sayid.)

Getting back on track, Dogen was willing to use subterfuge, deceit to kill Sayid, however you will notice he never lied. When Jack presses him, Dogen even tells him the truth, and still hopes Jack will do as he is asks. Later, Dogen continues to tell Jack the truth, even when it may not be advantageous. This is still further demonstrated when Dogen is speaking to Sayid, admitting he the pill was poison to kill him. He admits that he thinks Sayid would be better off dead.

Dogen is afraid of tipping his own balance toward the dark side. I think Dogen is very close to 50/50 in his balance, and he knows it wouldn't take much to tip the balance. Therefore, he is unwilling to repeatedly lie to others to accomplish his goals, because that would mean he would be a liar like Ben, and that would tip his scale toward darkness. Therefore, Dogen continues to tell the truth again and again, even when it hurts, even when it doesn't help his agenda.

If this is true, that means Dogen was speaking the truth to Sayid when he said he would be able to kill FLocke if he stabbed him before he spoke.