Ardent how?

[noob]

An ardent with both the Good and Evil (or Law and Chaos) mantles might share one or none of those alignment factors. For example, some good ardents seek to better understand the evil they combat by taking up the mantle of Evil, and the reverse is also true. Manifesting a power from an aligned mantle is considered an act of that alignment, however, so most ardents who take two opposed mantles are neutral.
So this means that I can become good just by manifesting protection against evil from the good mantle a whole lot of times?

[Psyren]

So this means that I can become good just by manifesting protection against evil from the good mantle a whole lot of times?

If you're committing evil acts somewhere else, no, just like casting a bunch of [good] spells won't make up for kicking puppies while you rape and pillage.

[MaxiDuRaritry]

If you're committing evil acts somewhere else, no, just like casting a bunch of [good] spells won't make up for kicking puppies while you rape and pillage.Especially if you're raping and pillaging said puppies.

[noob]

If you're committing evil acts somewhere else, no, just like casting a bunch of [good] spells won't make up for kicking puppies while you rape and pillage.

Except that casting a good spell is not a good action.

[ApologyFestival]

Except that casting a good spell is not a good action.
Book of Exalted Deeds disagrees, stating that casting good spells is unambiguously an act of good--a "concrete, positive means by which the heroes of the world fight against the darkness of evil". However, "Good spells don’t have any redemptive influence on those who cast them, for better or worse. An evil wizard who dabbles in a few good spells, most likely to help him achieve selfish ends, does not usually decide to abandon his evil ways because he’s been purified by the touch of the holy." The book then further considers ends and means.

In the case of this ardent, manifesting powers from the Good mantle is an act of good. However, what is their motive for doing so? If they are trying to selfishly change their alignment for personal gain, the ends are most certainly not good even if the means are.

[Psyren]

Except that casting a good spell is not a good action.

It is, but it's not one that impacts your alignment in a meaningful way - that was my point. I think we're actually on the same side here. You can't spam good spells or powers to gain enough "good points" to counteract evil acts.

[noob]

Except the clause where good spells do not redeem people is only said about spells and not psionic powers.
But there is no rules specifying when your alignment change from doing good actions or evil actions.(there is no defined treshold)
Except for some deeply evil actions but there is no deeply good action that change your alignment toward good.
But if you want to become good you can get your alignment changed by an Emissary of Barachiel.

[Psyren]

Still not sure why you're trying to argue with me when we're essentially saying the same thing, so I think I'll leave it there.

[noob]

Still not sure why you're trying to argue with me when we're essentially saying the same thing, so I think I'll leave it there.

The thing is that you are right but not due to how the rules are written but only because you do a reasoning that have nothing to do with any of the rules but which would be true in most ethics systems and then get a conclusion that is similar to the one of the rules(which is that it is impossible to determine if it is possible to become good by doing good actions when you also do evil actions).
As the rules are written there is no concept of good actions being unable or able to compensate for evil actions.
But since the rules never quantify the impact of good and evil actions on alignment then doing good or evil actions will not have a defined impact on your alignment.
(example:Saving all the good planes from being destroyed by the deepest evil by destroying that evil might be considered a good or evil action and would not have any defined impact on your alignment(someone could argue that you should become evil or good or neutral or not change alignment from that action and not be wrong))
So it is all up to the gm so you are right at your table when you are gm or when you are at the table of a gm who agrees with you which will be common.
But if there was a gm who decided "let us keep a good vs evil tract that shift X steps in one direction when doing a good or evil action" then at his table it could be possible to become good aligned just by casting a whole lot of good psionic powers.(but I think this table probably does not exists or it would have come up among the discussions about bad gms)

[Dimers]

Except the clause where good spells do not redeem people is only said about spells and not psionic powers.

Magic/psionics transparency is the default.