I believe for every drop of rain that falls, a flower grows.
I believe that somewhere in the darkest night, a candle glows.
I believe for everyone who goes astray, someone will come to show the way
—Roger Whittaker
Credit: Latin, vb (3rd pers. sing.): He, she or it believes.

Trust: a fundamental part of every legal, political, and financial system that has ever existed and one which cannot be solved by technology. Trust takes the single-round prisoner’s dilemma — in which a rational homo economicus would throw her conspirator under the bus — to the iterated prisoner’s dilemma, in which the logical thing is to cooperate, at least as long as your conspirator does.

Trust is a moral imperative, not a legal one. It derives its power from the very fact that it is not backed by any obligation. It is not a compulsion; it is a voluntary submission to the mercy of a third party in the hope of a reciprocal submission back.

Other variations:

A gentleman’s word is his bond.
“I meant what I said, and I said what I meant. An elephant’s faithful one-hundred per cent.”

To trust someone is to take a risk.

The desire to eliminate risk has become synonymous with the desire to eliminate the need for trust and confidence in individuals. In this contrarian’s opinion The Root of All Evil in the present system is the any social device which seeks to substitute data, policy , Rule, or algorithm for judgement, confidence, and trust.

So in the same way that rules, PlayBook, and policy override the judgement and confidence of and in individuals in large organisations, the desire to eliminate the need for trusted intermediaries in a distributed Ledger system has the same fundamental shortcoming.

By way of analogy, the conversion of a moral obligation (pick your children up promptly at the conclusion of today's session) with a financial one parents will be charged £10 per hour for late collection of children after the session -as in Dan Ariely's example of the childcare Centre) has the same effect.

Contrarian view: aspects of social relations like friendships, marketing, vacation placements with colleagues' children, which are today seen as an acceptable nepotism and indications of unfairness in the system, in fact tend to reinforce bonds of trust and confidence between existing market participants. This may be inequitable for new entrants to the market and those who have been disenfranchised (as they are systematically deprived of these opportunities to enter the market in favour of insiders) but they do tend to increase general levels of trust amongst those participants in the market

The answer maybe not to prevent these activites, but to try to ensure equivalents are put in place for those without the necessary connections.

What things tend to substitute financial for moral obligations? Contracts. Laws. Regulations. Code.