...however, my point is that you don't actually know what the benefits are of doing the right thing, except that it is highly likely that there will be benefits, even if small ones.

Conversely, doing the wrong thing probably means that the 'unintended consequences' are bad - getting caught etc.

You could take the documents and through thinking of 'I have struck gold' and nothing else, walk out of the cab and into the on-coming bus, to go under it and be rescued by the paramedics.

However, what I think you are getting at has been discussed regarding music.

Imagine finding a USB stick, making a perfect copy of it. When you get home you find that it contains the latest and as yet unreleased album by your favourite artist. Being good you don't post it onto youtube or even let your mates have a copy. However, even then the record label would deem you a pirate, if they found out. But we have had that argument.

Or...

The financial scenario: you find documents that Google are to make a cash bid for Facebook next week. You sell your mother and buy lots of shares in Facebook. The bid happens and you get to sell your shares, buy your mother back and make a tidy profit. Seems simple, victimless crime!

However, the documents could have been planted there (and elsewhere) by someone in the city with lots of shares to sell and wanting to 'secretly tip' the market so they profit. In this case you lose out on your investment and cannot buy your mother back.

Or Sergei and Brin find they have lost their documents in the back of the cab, see it as an omen, and don't go ahead with the bid.

However, if you did try and return the documents and were successfully able to do so, they might give you a T-shirt and a pat on the back for being good. They might even give you a job.

Here is a joyful parable:

The Parable of the Flowers

Believing in God is to believe in God's presence and uniqueness. This belief saves the person from meaninglessness and from being errant. Assuming that lies would make a person happy is to go after a dream that will never come true. Reality is God's consent.

In old times, there was a sagacious emperor, and his people loved him. But the emperor was enduring an absence; he did not have a son or a daughter. After a while, the emperor decided to adopt a child.

Public criers shouted, "Listen to me people! On Friday our emperor will adopt a child. This child must be a ten year-old boy; our emperor will leave his throne to his foster son, and he will rest. The people who want to give their sons to the emperor should gather in front of the palace on Friday."

Before the crier finished talking, the public square in front of the palace became full of ten year-old boys.

The emperor gave flower seeds to each boy, and declared his condition: "After sowing these seeds and growing them, you should bring me a bunch of flowers. Of whose flowers that I become fond of, that boy will become my adopted son. You have three months; after this period it is our decision to gather in this same place."

Three months passed. The emperor went to the square and saw that the square was full of beautiful flowers with different colors. The boys who had taken the seeds were waiting for the happy moment.

The emperor looked attentively at the boys while passing near them without stopping.

At another corner stood a boy crying who had no flowers in his hands. The emperor went near the boy, and stopped. He asks:

"Why are you crying?"

The boy spoke of his trouble:

"My emperor, the seeds that your Excellency has given me did not grow despite my efforts. I tried everything, but in vain. I am weeping because you will not adopt me since I do not have any flowers."

The emperor replied, "Do not cry because of that, because I will adopt you as my son. Your seeds did not become flowers because I boiled them before giving them to you. These people who have brought flowers think that they can deceive me. Their flowers are not from my seeds. They found them somewhere else" said the emperor and hugged the boy.

"You told me the truth; you did not lie to me. Listen carefully, it is the person who accepts the truth, not the liar, who will become happy in the end."