Comments and remarks on the writings of Adam Smith's Theory of Moral Sentiments
The ends justify the means, always. That is, of course, the very premise of the decision to execute any means to achieve any end, independent of the notions of good or evil, of merit or demerit. The debate, then, about whether the ends justify the means, that society or any congregated group might have, is not actually about whether the ends justify the means, it is whether the group can enter into a sympathy with the motives of the subject who executed the actions in question. For, to that subject, had the ends not justified the means, there would have necessarily been no execution of the action, for the subject would not act irrationally, despite what a spectator might so observe. The question, then, is not in justification of the actions by the executor's logical (or perhaps illogical) basis, but rather, in the group's agreement or disagreement of the magnitude of the actions undertaken.
Should the group, or society, think that the magnitude of the actions taken is within reason and the subject acted rationally, they will not condemn his actions as too bold, too rash, or too disproportionate. A subject who steals to feed his family very well may be judged to have broken the laws of society, but as the society can more easily enter into the rationale and motives of the subject, the magnitude of the actions does not seem as extreme, and the ends can be seen to justify the means. Conversely, society would necessarily disapprove of the means of a murder of one by another over a minor inconvenience; such ends are far too great in proportion to the means, it may be judged, but necessarily, to the murderer, the response of action was justified, lest they would not have done it.
To translate this through is to say that one's approval, or disapproval, of another's actions is entirely subjective within the bounds of the observer's ability to enter into a sympathy with the action's executioner. As such, a question of the end justifying the means is hardly a logical one to ask, as the answer must, by virtue of the means having been executed, be yes. Instead, if I may say so, shift your paradigm to understand that knowing, to oneself, the ends will always justify the means. From that understanding, then, and as a course of diligent decision-making, ask oneself, about any action you are about to undertake, what a third party may say about the proportionate, or disproportionate, degree of the actions in question. One can always justify their actions to themselves, lest they would not do it, so inclusion of a metric of a third party may give the insight required to make a sound, logical decision.