Exploring Kantian Ethics: The Moral Implications of Lies of Omission

Recently, I've been contemplating a philosophical dilemma revolving around lies of omission, or when someone intentionally withholds relevant information, leading the other person to believe something untrue, and whether they align with Kant's principles of deontological ethics (read my blog post on Kant for background information). As per lying, Kant believes one can never lie no matter the time or circumstance due to the categorical imperative: Act according to the maxim that you would wish all other rational people to follow, as if it were a universal law. If lying is made a universal law then society would collapse and therefore lying is immoral. Therefore, when the axe murderer asks Kant for his prey, Kant would have to tell the murderer (but maybe this is a gross oversimplification that will be explained later). However, what would Kant's position be on lies of omission (if it is even a thing?)? On one hand, "lies” of omission would not be an act of deception as there is no immoral action involved as not speaking is inaction. Therefore, one is still withholding a lie, and withholding a lie could be made a universal law, or rather nothing can be made a universal law since there is no action. On the other hand, perhaps it is still an action. An action of not doing an action - not speaking the truth. If that is the case then if one applied withholding the truth as a universal law that would be immoral according to Kant. Or it could be the case that a lie of omission is a "soft" lie and not a "hard" lie and therefore it is moral if this division of lies exists. But then again, with a soft lie, there is deception and therefore immoral according to some.

One could argue that the same logic applies to lies of omission as it does to regular lies for Kant, and thus tend to think of most lies of omission not as inaction, but incomplete action, insofar as there is generally action taken to narrate some sort of story in a way that is not fully completing the story.
         However, according to American philosopher, Allen W. Wood, in his Kantian Ethics, 

“By contrast, an untruthful statement that does not amount to a 'declaration,' is merely a falsiloquium -- merely a "falsification" (p. 240). While many of the details of the discussion of lying remain (regarding especially what a proper Kantian response should be to the different case of a murderer at the door) it should certainly be enough here just to include a passage from Kant's ethical lectures that I, at least, had never seen (nor seen anyone mention) before I read this book. Regarding the general topic of committing a falsiloquium, of saying something intentionally untrue when there is no 'declaration' in play, Kant says that:

‘I can also commit a falsiloquium when my intent is to hide my intentions from the other, and he can also presume that I shall do so, since his own purpose is to make a wrongful use of the truth. If an enemy, for example, takes me by the throat and demands to know where my money is kept, I can hide the information here, since he means to misuse the truth. That is still no mendacium.’

What this means is that if someone shows up at the door with murderous intent, and if, in addition to that, she is not in a position to demand a 'declaration' from me, then I can indeed, on Kant's view, tell her something intentionally untruthful. As Kant understands this technical notion, that is still no lie.”

Overall, what this is saying is that there is no lie since the thief knows that one will withhold the information and the thief has no right to demand the truth. However, if you did speak to the thief and told them incorrect information, you are a liar and your action is immoral according to Kant. You can argue it both ways I suppose. However, if it is the case that a lie of omission is not immoral, then it is no part of Kant's theory to hold that just anyone, including an axe murderer, who knocks on your door is automatically in a position to require from you information regarding the present whereabouts of some person. Yet, one could extend this to justify lying to the axe murderer as the greater context of saving another and the lack of necessity of the declaration to him outweighs sin of lying or would not be considered a lie in this situation. On the other hand, to tell the axe murderer a lie, while you have done to him no wrong; since he plots to murder another and he cannot complain about it, you are still a liar nonetheless, since I have acted contrary to the right of humanity, according to the categorical imperative.