So what is money anyway? Let’s consider the origin and basis of property. I think a good place to start here is John Locke’s second treatise on Government, where he says (this is a long quotation):

Sect. 27. Though the earth, and all inferior creatures, be common to all men, yet every man has a property in his own person: this no body has any right to but himself. The labour of his body, and the work of his hands, we may say, are properly his. Whatsoever then he removes out of the state that nature hath provided, and left it in, he hath mixed his labour with, and joined to it something that is his own, and thereby makes it his property. It being by him removed from the common state nature hath placed it in, it hath by this labour something annexed to it, that excludes the common right of other men: for this labour being the unquestionable property of the labourer, no man but he can have a right to what that is once joined to, at least where there is enough, and as good, left in common for others.

Sect. 45. Thus labour, in the beginning, gave a right of property, wherever any one was pleased to employ it upon what was common, which remained a long while the far greater part, and is yet more than mankind makes use of. Men, at first, for the most part, contented themselves with what unassisted nature offered to their necessities: and though afterwards, in some parts of the world, (where the increase of people and stock, with the use of money, had made land scarce, and so of some value) the several communities settled the bounds of their distinct territories, and by laws within themselves regulated the properties of the private men of their society, and so, by compact and agreement, settled the property which labour and industry began; and the leagues that have been made between several states and kingdoms, either expresly or tacitly disowning all claim and right to the land in the others possession, have, by common consent, given up their pretences to their natural common right, which originally they had to those countries, and so have, by positive agreement, settled a property amongst themselves, in distinct parts and parcels of the earth; yet there are still great tracts of ground to be found, which (the inhabitants thereof not having joined with the rest of mankind, in the consent of the use of their common money) lie waste, and are more than the people who dwell on it do, or can make use of, and so still lie in common; tho' this can scarce happen amongst that part of mankind that have consented to the use of money.

Sect. 46. The greatest part of things really useful to the life of man, and such as the necessity of subsisting made the first commoners of the world look after, as it cloth the Americans now, are generally things of short duration; such as, if they are not consumed by use, will decay and perish of themselves: gold, silver and diamonds, are things that fancy or agreement hath put the value on, more than real use, and the necessary support of life. Now of those good things which nature hath provided in common, every one had a right (as hath been said) to as much as he could use, and property in all that he could effect with his labour; all that his industry could extend to, to alter from the state nature had put it in, was his. He that gathered a hundred bushels of acorns or apples, had thereby a property in them, they were his goods as soon as gathered. He was only to look, that he used them before they spoiled, else he took more than his share, and robbed others. And indeed it was a foolish thing, as well as dishonest, to hoard up more than he could make use of. If he gave away a part to any body else, so that it perished not uselesly in his possession, these he also made use of. And if he also bartered away plums, that would have rotted in a week, for nuts that would last good for his eating a whole year, he did no injury; he wasted not the common stock; destroyed no part of the portion of goods that belonged to others, so long as nothing perished uselesly in his hands. Again, if he would give his nuts for a piece of metal, pleased with its colour; or exchange his sheep for shells, or wool for a sparkling pebble or a diamond, and keep those by him all his life he invaded not the right of others, he might heap up as much of these durable things as he pleased; the exceeding of the bounds of his just property not lying in the largeness of his possession, but the perishing of any thing uselesly in it.

Sect. 47. And thus came in the use of money, some lasting thing that men might keep without spoiling, and that by mutual consent men would take in exchange for the truly useful, but perishable supports of life.

Sect. 48. And as different degrees of industry were apt to give men possessions in different proportions, so this invention of money gave them the opportunity to continue and enlarge them: for supposing an island, separate from all possible commerce with the rest of the world, wherein there were but an hundred families, but there were sheep, horses and cows, with other useful animals, wholsome fruits, and land enough for corn for a hundred thousand times as many, but nothing in the island, either because of its commonness, or perishableness, fit to supply the place of money; what reason could any one have there to enlarge his possessions beyond the use of his family, and a plentiful supply to its consumption, either in what their own industry produced, or they could barter for like perishable, useful commodities, with others? Where there is not some thing, both lasting and scarce, and so valuable to be hoarded up, there men will not be apt to enlarge their possessions of land, were it never so rich, never so free for them to take: for I ask, what would a man value ten thousand, or an hundred thousand acres of excellent land, ready cultivated, and well stocked too with cattle, in the middle of the inland parts of America, where he had no hopes of commerce with other parts of the world, to draw money to him by the sale of the product? It would not be worth the enclosing, and we should see him give up again to the wild common of nature, whatever was more than would supply the conveniencies of life to be had there for him and his family.

Sect. 49. Thus in thebeginning all the world was America, and more so than that is now; for no such thing asmoney was any where known. Find out something that hath the use and value of money amongst his neighbours, you shall see the same man will begin presently to enlarge his possessions.

Sect. 50. But since gold and silver, being little useful to the life of man in proportion to food, raiment, and carriage, has its value only from the consent of men, whereof labour yet makes, in great part, the measure, it is plain, that men have agreed to a disproportionate and unequal possession of the earth, they having, by a tacit and voluntary consent, found out, a way how a man may fairly possess more land than he himself can use the product of, by receiving in exchange for the overplus gold and silver, which may be hoarded up without injury to any one; these metals not spoiling or decaying in the hands of the possessor. This partage of things in an inequality of private possessions, men have made practicable out of the bounds of society, and without compact, only by putting a value on gold and silver, and tacitly agreeing in the use of money: for in governments, the laws regulate the right of property, and the possession of land is determined by positive constitutions.