Have lots of experiments, but make sure they're strategically focused.

The value of any commodity, therefore, to the person who possesses it, and who means not to use or consume it himself, but to exchange it for other commodities, is equal to the quantity of labour which it enables him to purchase or command. Labour, therefore, is the real measure of the exchangeable value of all commodities. The real price of everything, what everything really costs to the man who wants to acquire it, is the toil and trouble of acquiring it.

Though our brother is upon the rack, as long as we ourselves are at ease, our senses will never inform us of what he suffers. They never did and never can carry us beyond our own persons, and it is by the imagination only that we form any conception of what are his sensations...His agonies, when they are thus brought home to ourselves, when we have this adopted and made them our own, begin at last to affect us, and we then tremble and shudder at the thought of what he feels.

In general, if any branch of trade, or any division of labour, be advantageous to the public, the freer and more general the competition, it will always be the more so.

But poverty, though it does not prevent the generation, is extremely unfavourable to the rearing of children. The tender plant is produced, but in so cold a soil, and so severe a climate, soon withers and dies.

I have no great faith in political arithmetic, and I mean not to warrant the exactness of either of these computations.

The annual labour of every nation is the fund which originally supplies it with all the necessaries and conveniencies of life which it annually consumes, and which consist always either in the immediate produce of that labour, or in what is purchased with that produce from other nations.