When people commit to principles, they often consider one transgression ruinous to the whole agenda. Eating a sausage by drunken accident can end years of vegetarianism.

As a child I thought this crazy. Couldn’t vegetarians just eat meat when it was cheap under their rationale? Scrumptious leftovers at our restaurant, otherwise to be thrown away, couldn’t tempt vegetarian kids I knew. It would break their vegetarianism. Break it? Why did the integrity of the whole string of meals matter?  Any given sausage was such a tiny effect.

I eventually found two explanations. First, it’s easier to thwart temptation if you stake the whole deal on every choice. This is similar to betting a thousand dollars that you won’t eat chocolate this month. Second, commitment without gaps makes you seem a nicer, more reliable person to deal with. Viewers can’t necessarily judge the worthiness of each transgression, so they suspect the selectively committed of hypocrisy. Plus everyone can better rely on and trust a person who honors his commitments with less regard to consequence.

There’s another good reason though, which is related to the first. For almost any commitment there are constantly other people saying things like ‘What?! You want me to cook a separate meal because you have some fuzzy notion that there will be slightly less carbon emitted somewhere if you don’t eat this steak?’ Maintaining an ideal requires constantly negotiating with other parties who must suffer for it. Placing a lot of value on unmarred principles gives you a big advantage in these negotiations.

In negotiating generally, it is often useful to arrange visible costs to yourself for relinquishing too much ground. This is to persuade the other party that if they insist on the agreement being in that region, you will truly not be able to make a deal. So they are forced to agree to a position more favorable to you. This is the idea behind arranging for your parents to viciously punish you for smoking with your friends if you don’t want to smoke much. Similarly, attaching a visible large cost – the symbolic sacrifice of your principles – to relieving a friend of cooking tofu persuades your friend that you just can’t eat with them unless they concede. So that whole conversation is avoided, determined in your favor from the outset.

I used to be a vegetarian, and it was much less embarrassing to ask for vegetarian food then than was afterward when  I merely wanted to eat vegetarian most of the time. Not only does absolute commitment get you a better deal, but it allows you to commit to such a position without disrespectfully insisting on sacrificing the other’s interests for a small benefit.

Prompted by The Strategy of Conflict by Thomas Schelling.