Yet more serious criticism may be directed against the theory of the industrial reserve army, the theory wherein Marx attempts to sum up the law of population of the capitalist era. For the theory is wholly based upon the premise that the conversion of wage capital into technical capital is competent to bring about the permanent unemployment of labour, or definitively to reduce the demand for labour. Now this premise will not hold, for technical capital, by promptly increasing the profit of capital, and by lowering the price of the product in the long run, provides for the capitalist, first of all, and subsequently for the consumer, the possibility of fresh savings, and these in the end create a further demand for labour, so that sooner or later there will be a call upon the active services of the workers who are temporarily unemployed. Vain, therefore, is any attempt to make technical capital responsible for the relative excess of population, which technical capital cannot possibly produce, for this phenomenon must be referred to the presence and to the activity of a very different variety of capital, and one not considered by Marx, namely unproductive capital.

But these criticisms, which after all touch no more than points of detail, are mere trifles in comparison with the incurable contradictions in which the author's fundamental theory is involved. In fact, by a vigorous deduction from his premise that the value of commodities is measured by the mass of labour incorporated in them, Marx arrives at the fundamental and logical distinction between constant capital and variable capital. If, however, the value of products be exclusively determined by the mass of labour incorporated in them, it is evident that the capital invested in machinery or in raw material can only transmit to the product a value exactly equal to the quantity of labour contained therein, without adding any surplus, and that it is therefore constant capital; whereas wage capital transmits to the product value equal to all the quantity of labour which it maintains and sets in motion, a quantity which, as we know, exceeds the quantity of labour contained in the capital itself. In other words, wage capital, besides reproducing its own value, furnishes a supplement or a surplus value, and is therefore variable capital. Consequently surplus value arises exclusively from variable capital, and is therefore precisely proportional to the quantity of this capital.

It further ensues that of two undertakings employing equal amounts of aggregate capital, the one which employs a larger proportion of constant capital ought to furnish a profit and a rate of profit lower than that furnished by the other. But free competition among the capitalists enforces an equal rate of profit upon the capitals invested in the various undertakings, and leads to the immediate abandonment of undertakings requiring a greater proportion of constant capital, and to the correlative expansion of the others. There consequently results an increase in the value of the products of the former undertakings, and a diminution in the value of the products of the latter. This process continues until the value of the respective products furnishes an equal rate of profit to the capitals respectively employed in producing them. Value, therefore, though in the first instance it is equivalent to the labour employed in producing the products, necessarily diverges from that standard in the end, and has then an utterly different measure. Thus the theory we are discussing is peremptorily refuted, or is reduced to absurdity.

From the outset Marx is distinctly aware of the existence of this striking contradiction, which emerges in so formidable a manner in the first stage of his investigation; he frankly recognises it, but postpones its solution to the later volumes of his treatise. On the very morrow, indeed, of the publication of the first volume, he ardently set to work once more, and sketched to his friend, in monumental pages, the design of the complete book. Just as St. Augustine was grieved that the duties of his episcopate deprived him of the hours which he would have preferred to devote to the writing of a volume to be the crown of his City of God, so Marx was harassed by the thought of the time which the work of party organisation filched from his scientific labours, and it was solely that he might escape from the absorbing engagements involved in the former task that in the Hague congress of 1872 he proposed the transfer of the International to New York.

But now we unexpectedly reach a "dead point" in the biography of our thinker, for his mental life, otherwise so normal and so brilliant, here suddenly becomes obscured, and is tinged with mystery and enigma. For, on the one hand, Marx clearly affirmed, and showed by his actions, that he definitely wished to devote himself to the completion of his treatise, whereas, on the other hand, it is undeniable that after the publication of the first volume of Capital, he never wrote another line of the book, and that all the posthumous additions to this volume were composed prior to 1867. I do not mean to imply that during subsequent years he gave himself up to inertia or repose, for it was during this period that he wrote all the economic section in Engels' booklet against Dühring; he learned Russian; he read the agricultural statistics of numerous countries and the reports on poverty in Ireland; he studied the matriarchal system; carried on ingenious discussions with Engels concerning Carey's theory of rent and Bastiat's theory of the cost of reproduction; threw light on the influence of fluctuations in the value of money upon the rate of profit; sketched a mathematical theory of commercial cycles—in a word, his thought-process remained so active that when a certain publisher asked for the right to issue his complete works, he replied, "My works, those which represent my present thought, are not yet written." But the essential work of his life, the work which had been so much cherished and which he again and again turned over in his thoughts, seems, as far as palpable traces are concerned, to have been entirely dismissed from his mind. We thus look on, marvelling and grieved, at the sight of the enfeebled hero withdrawing from the field, what time his banner, whose staff is not yet firmly implanted in the ground, is left as a target for the easy assaults of his emboldened adversaries.

There certainly contributed to this intellectual shipwreck the illnesses and the misfortunes from which Marx suffered during the later years of his life. His health had been gravely undermined by overwork during the composition of the first volume of Capital and during the task of proletarian organisation; trouble from boils alternated with bronchitis, liver disorder, headache, and lumbago. In vain did he seek health in gentler climes, at Ramsgate, Ventnor, Neuenahr, Carlsbad, Algiers, Monte Carlo, Vevey, and other fashionable health resorts. All attempts at cure proving inefficacious, he had at length to settle down once more in London.

In 1881 occurred the death of his wife; while the death of his beautiful daughter Jenny, Longuet's wife, in January, 1883, was, if possible, a yet more cruel blow. Marx never recovered from this last shock; henceforward he was a broken man, the mere shadow of his former self; he passed his time contemplating the portraits of his two dear ones which Engels was to bury with him, and he no longer took any interest in the world around him or in the social tumult of which he was the inspirer and the originator. He died suddenly at two in the afternoon of March 14, 1883, while seated in his study chair. The titanic brain, which had given a new world to humanity, which had broken once for all the spiritual and material bondage of mankind, had ceased to live and to vibrate.

Most distressing of all, he had taken with him to the grave the solution of the formidable enigma which everyone, the vulgar and the thinkers alike, had expected his genius to solve, and which no one else could unravel. It is true that shortly before his death he showed his friend the bulky manuscripts dictated in earlier days relating to the Criticism of Political Economy, suggesting that something might be made of this collection. It is also true that Engels, faithful executor of his divinity's wishes, devoted himself with splendid zeal to the publication of the manuscripts. But alas what delusion was in store for the admirers of the master! What a Russian campaign of disaster organised by enthusiastic lieutenants to the hurt of this Napoleon of thought!

In 1885, two years after the death of Marx, there was published under Engels' supervision a so-called second volume of Capital. But the careless and pedestrian editorship, the long theoretical disquisitions making no appeal to facts for their justification, disquisitions in which the argumentative thread is continually broken, suffice to show that what we have before us is not a book, hardly even a sketch for a book, but a series of casual writings composed for the purposes of study and for personal illumination. Moreover, the work is wholly devoted to uninspiring monetary discussions upon the circulation of capital, to dissertations concerning fixed and circulating capital, the formation of metallic reserves, the circulation of commodity-capital, etc.