He was professor of jurisprudence and political economy in Queen's College, Belfast, noted for challenging the Wages-Fund doctrine[2] and for addressing contemporary agrarian policy questions.

The duties of this chair requiring only short visits to Ireland in certain terms of each year, he continued to reside and pursue his studies in London, and became a frequent writer on economic and social questions in the principal reviews and other periodicals.

JS Mill gave a full account of the contents of this work in a paper in the Fortnightly Review, in which he pronounced Leslie to be one of the best living writers on applied political economy.

Mill had sought his acquaintance on reading his first article in Macmillan's Magazine; he admired his talents, took pleasure in his society, and treated him with a respect and kindness which Leslie always gratefully acknowledged.

To the memory of the former of these he afterwards paid a graceful tribute in a biographical sketch (Fortnightly Review, February 1881); and to the close of his life there existed between him and M. de Laveleye relations of mutual esteem and cordial intimacy.

He had long contemplated, and had in part written, a work on English economic and legal history, which would have been his magnum opus, a more substantial fruit of his genius and his labours than anything he has left.

But the manuscript of this treatise, after much pains had already been spent on it, was unaccountably lost at Nancy in 1872; and, though he hoped to be able speedily to reproduce the missing portion and finish the work, no material was left in a state fit for publication.

Cliffe Leslie defended the inductive method in political economy, against the attempt to deduce the economic phenomena of a society from the so-called universal principle of the desire of wealth.

Maine's personal teaching of jurisprudence, as well as the example of his writings, led Cliffe Leslie to look at the present economic structure and state of society as the result of a long evolution.

[5] The earliest writing in which Leslie's revolt against the so-called orthodox school distinctly appears is his Essay on Wages, first published in 1868 and reproduced as an appendix to the volume on Land Systems.

In this, after criticism of the Wages-Fund doctrine and the lack of agreement between its results and the observed phenomena, he concludes by declaring that political economy must be an inductive, instead of a purely deductive science.

Those who share his views on the philosophical constitution of the science regard the work he did, notwithstanding its unsystematic character, as in reality the most important done by any English economists in the latter half of the 19th century.

But even the warmest partisans of the older school acknowledge that he did excellent service by insisting on a kind of inquiry, previously too much neglected, which was of the highest interest and value, in whatever relation it might be supposed to stand to the establishment of economic truth.

The members of both groups alike recognised his great learning, his patient and conscientious habits of investigation and the large social spirit in which he treated the problems of his science.