In the Republic, Plato discusses with Adeimantus the benefits of specialization and the division of labor.

A central figure in Western philosophy, Plato was founder of the Academy in Athens, student of Socrates and teacher of Aristotle.

Then, I said, let us begin and create in idea a State; and yet the true creator is necessity, who is the mother of our invention.

Of course, he replied.

Now the first and greatest of necessities is food, which is the condition of life and existence.

Certainly.

The second is a dwelling, and the third clothing and the like.

True.

And now let us see how our city will be able to supply this great demand: We may suppose that one man is a husbandman, another a builder, some one else a weaver—shall we add to them a shoemaker, or perhaps some other purveyor to our bodily wants?

Quite right.

The barest notion of a State must include four or five men.

Clearly.

And how will they proceed? Will each bring the result of his labours into a common stock?—the individual husbandman, for example, producing for four, and labouring four times as long and as much as he need in the provision of food with which he supplies others as well as himself; or will he have nothing to do with others and not be at the trouble of producing for them, but provide for himself alone a fourth of the food in a fourth of the time, and in the remaining three fourths of his time be employed in making a house or a coat or a pair of shoes, having no partnership with others, but supplying himself all his own wants?

Adeimantus thought that he should aim at producing food only and not at producing everything.

Probably, I replied, that would be the better way; and when I hear you say this, I am myself reminded that we are not all alike; there are diversities of natures among us which are adapted to different occupations.

Very true.

And will you have a work better done when the workman has many occupations, or when he has only one?

When he has only one.

Further, there can be no doubt that a work is spoilt when not done at the right time?

No doubt.

For business is not disposed to wait until the doer of the business is at leisure; but the doer must follow up what he is doing, and make the business his first object.

He must.

And if so, we must infer that all things are produced more plentifully and easily and of a better quality when one man does one thing which is natural to him and does it at the right time, and leaves other things.

Undoubtedly.

Then more than four citizens will be required; for the husbandman will not make his own plough or mattock, or other implements of agriculture, if they are to be good for anything. Neither will the builder make his tools—and he too needs many; and in like manner the weaver and shoemaker.

True.

Then carpenters, and smiths, and many other artisans, will be sharers in our little State, which is already beginning to grow?

True.

Yet even if we add neatherds, shepherds, and other herdsmen, in order that our husbandmen may have oxen to plough with, and builders as well as husbandmen may have draught cattle, and curriers and weavers fleeces and hides,—still our State will not be very large.

That is true; yet neither will it be a very small State which contains all these.

Then, again, there is the situation of the city—to find a place where nothing need be imported is wellnigh impossible.

Impossible.

Then there must be another class of citizens who will bring the required supply from another city?

There must.

But if the trader goes empty-​handed, having nothing which they require who would supply his need, he will come back empty-​handed.

That is certain.

And therefore what they produce at home must be not only enough for themselves, but such both in quantity and quality as to accommodate those from whom their wants are supplied.

Very true.

Then more husbandmen and more artisans will be required?

They will.

Not to mention the importers and exporters, who are called merchants?

Yes.

Then we shall want merchants?

We shall.

And if merchandise is to be carried over the sea, skilful sailors will also be needed, and in considerable numbers?

Yes, in considerable numbers.

Then, again, within the city, how will they exchange their productions? To secure such an exchange was, as you will remember, one of our principal objects when we formed them into a society and constituted a State.

Clearly they will buy and sell.

Then they will need a market-​place, and a money-​token for purposes of exchange.

Certainly.

Suppose now that a husbandman, or an artisan, brings some production to market, and he comes at a time when there is no one to exchange with him,—is he to leave his calling and sit idle in the market-​place?

Not at all; he will find people there who, seeing the want, undertake the office of salesmen. In well-​ordered states they are commonly those who are the weakest in bodily strength, and therefore of little use for any other purpose; their duty is to be in the market, and to give money in exchange for goods to those who desire to sell and to take money from those who desire to buy.

This want, then, creates a class of retail-​traders in our State. Is not ‘retailer’ the term which is applied to those who sit in the market-​place engaged in buying and selling, while those who wander from one city to another are called merchants?

Yes, he said.

And there is another class of servants, who are intellectually hardly on the level of companionship; still they have plenty of bodily strength for labour, which accordingly they sell, and are called, if I do not mistake, hirelings, hire being the name which is given to the price of their labour.

True.

Then hirelings will help to make up our population?

Yes.

And now, Adeimantus, is our State matured and perfected?

I think so.