Thomas Clarkson was as convinced as his fellow founders of the Society for the Abolition of the Slave Trade that slavery was offensive to law and to Christianity. But he saw that overcoming the strength of the slavocracy (especially the "sugar lobby" of rich planters from the West Indies) would need arguments based on economics as well. A prodigious and indefatigable researcher, Clarkson gathered evidence for such arguments. In his Essay on the Impolicy of the African Slave Trade (1788), he contended that, once all the sums were done correctly, the slave trade could be shown to be uneconomic.

I have now considered the abolition of the slave trade as far as it would have an influence on the present or future number of the slaves: I come now to the second point of inquiry, namely, to consider the immediate or future effect which it would have upon the planters, the slaves themselves, and the islands: for it has been said, that many other melancholy consequences would arise to these by the abolition of the trade.

The first effect, that the planter would immediately experience, would be this. He would save the money formerly expended in the purchase of new slaves, and of course avoid the inconceivable difficulties which he has now necessarily to encounter on this account.

That the reader may form a notion of the distress under which he frequently labours from this circumstance, and of the advantages resulting from the change, I shall give him the sentiments of Mr. Long, who was too much attached to the interests of his friends in the islands, to deceive them in this particular.

"The purchase of new negroes (says he) is the most chargeable article attending these estates, and the true source of the distresses, under which their owners suffer: for they involve themselves so deeply in debt to make these inconsiderate purchases, and lose so many by disease or other means in the reasoning, that they become unable to make good their engagements, are plunged in law suits and anxiety; while for want of some prudent regulation in the right husbanding of their stock, and promoting its increase by natural means, they intail upon themselves a necessity of drawing perpetual recruits of unseasoned Africans, the expense of which forms only a new addition to their debts and difficulties."

To confirm this, I shall state a few particular facts. In the island of Jamaica four courts are annually held, namely, in the months of February, May, August, and November. Ab , out three thousand new actions are usually brought at each of these, chiefly on bonds; and of these bonds about nine-tenths are such as have been given to the factors for new slaves.

In the same island about five hundred thousand pounds passed through the hands of a certain sheriff in three years. This prodigious sum had been procured by the sale of goods, taken chiefly on execution on such bonds, as had been given for the same purpose as the former.

The principal part of those who were co ed in the goals of the same island, during the same period, consisted of people whose persons had been seized, after the issuing out of executions on judgment, to make up that deficiency in their payment for slaves, to which their goods had not been found adequate.

It is easy to see from hence, and the foregoing quotation from Mr. Long, that I have not been stating a visionary or c erical advantage. The planter, in consequence of the regulations that would unavoidably follow the abolition of the slave trade, would protract the lives of his present slaves. In the interim, the rising generation would be shooting up. To save therefore the purchase-money usually expended in these, to be freed from a source of continual inquietude and distress, and at the same time to experience no diminution in the returns of his estate, is an advantage so substantial and important at the first sight, as to need no farther illustration.

There is a second, however, which he would also immediately feel. His slaves would become more valuable. Whatever may be his property in these at the present moment, certain it is, that, on the moment of the abolition of the slave trade, it would be considerably increased.

But his future would be tely greater than his present advantages. His slaves, which would become immediately more valuable in consequence of the abolition, would, in process of time, become more valuable from. another consideration. Let us view them therefore at a distant period. Let us see their situation in about twenty years, after this cg-eat event has taken place.

At this period, it is to be presumed, that all the slaves in the islands would be Creoles.

In the first place, they would have been inured from their infancy, in a regular gradation of employment, to labour. They would of course be more hardy, and capable of the plantation work, than any of their predecessors, who, having led, perhaps, a life of indolence in their own country, have been but little capable of sustaining the fatigue which they have been sentenced to undergo.

They would, secondly, be more ready and expert. Born on the islands, they would attain our language, and understand us immediately: whereas, their predecessors, the imported Africans, have been unable, for a length of time, to comprehend our meaning.

These circumstances would greatly increase their price, if exposed to sale, and of course the property of their possessors: and as a proof of it, I appeal to the planter, whether he does not consider a Creole, at this moment, of twice the value of an imported slave.

His work would be better done This is evident from the habit of labour, which his slaves would have acquired from their infancy, and (if I may be allowed the expression) their apprenticeship to their work.

More of it would be done in the same time. This may appear a paradox to many. But the labour of those slaves, who are ruled with a rod of iron, is inconceivably small. … But, reverse the scene. Let him be treated with tenderness. Let his wants be supplied. This will operate as an incitement to his exertions: gratitude will demand a return; and his labour will carry with it, wherever it is traced, distinguishing marks of the change. This is not merely a speculative position. It is founded on experience. Many planters have been witnesses of the fact.

This change having once taken place, and great benefit having necessarily arisen to the planter from the adoption of it, there can be no difficulty in anticipating the future situation of the slave; for it is natural to suppose, that if advantages should have been found to accrue to the planter in proportion to his humanity, he would still proceed; and when that system, which was the consequence of the abolition of the slave trade, had had its due operation, he would adopt a second still more lenient and equal. Every new indulgence of this kind would advance the slave in the scale of social life, and improve his condition. Every improvement of his condition would q ualify him the more for the reception of Christianity and freedom; and if ever these glorious events were to be brought to pass, then would be the aera, in which happiness would be the most extensively diffused in the colonies, and the estate of the planter be productive of the greatest gain.

I come now to the consequences which would result to the islands by the abolition of the slave trade. ...

In a few years all the slaves upon the islands would be Creoles, and as every man has naturally an attachment to his native spot, so the Creole would have a partiality for these. In these islands also would be his relatives and friends, his little property, his spot of nutrition, and his home. He would speak the same language as his master, contract the same habits, imbibe the same prejudices. These, and other circumstances, would excite his alacrity, his vigilance, his courage, his exertions, and he would be found to the islands a steady and faithful protector, and to the invaders a bitter and a formidable foe.

I have now enumerated the principal consequences that would unavoidably result to the planters) the slaves themselves, and the islands, from the abolition of the slave trade. I need not observe, that they are such, as are highly important in themselves, truly pleasing in the anticipation, and most devoutly to be prayed for. Indeed, there is no prospect, that we are obliged to view at a distance, that is so charming and delightful. For let us see the planter at a future period, not the tyrant and destroyer, but the shepherd and the guardian of his slaves. Let us see them looking upon him in return as the dispenser of their blessings; gratefully acknowledging his favours, endeared to him from the ties of principle and gratitude. Let us see them annually improving both in their temporal and religious state. Then shall the chains of despotism be broken. The Daemon torture shall throw her instruments into the sea; commerce extend her swelling sails; embarrassments be no more; security and confidence established; a golden age, in short, reign in the colonial plains; and a spot, that was once the scene of accumulated persecution and murder, be the mansions of peace, security, happiness, and joy.