‘Once I have said I will do a thing, I do it’ – this mode of thinking counts a sign of possessing character. How many actions have been done, not because they were chosen as the most rational, but because when they occurred to us, they in some way tickled our vanity and ambition, so that we stuck with them and blindly carried them out! In this way they increase our belief in our own character and our good conscience, and thus in general our strength; while the choice of the most rational course keeps alive skepticism towards us and to this extent a feeling of weakness.
Why is the stability of our own identities, or even our life choices, so important? One possibility has to do with simple rationalization: Once we make a choice, we want to justify it—especially if it’s one we don’t see ourselves unmaking. In other contexts, we see this phenomenon play out all the time: We value objects more once we’ve purchased them, and hold offhand opinions far more strongly once we’ve stated them out loud. “It makes sense to me that people are motivated to believe that their current lifestyle decisions are superior to other options,” says social psychologist Eli Finkel, whose own research focuses on interpersonal relationships and conflict, “rather than an arbitrary choice draw from those options.”