The merit of Marx is that he suddenly produces a qualitative change in the history of social thought. He interprets history, understands its dynamic, predicts the future, but in addition to predicting it (which would satisfy his scientific obligation), he expresses a revolutionary concept: the world must not only be interpreted, it must be transformed. Man ceases to be the slave and tool of his environment and converts himself into the architect of his own destiny.

Marx's ideas became the doctrines inspiring the labour and socialist movements of most of Europe. Mainly via Lenin and the Russian Revolution they became the quintessential international doctrine of twentieth-century social revolution, equally welcomes as such from China to Peru. Through the triumph of parties identified with these doctrines, versions of these ideas became the official ideology of the states in which, at their peak, something like a third of the human race lived, not to mention political movements of varying size an importance in the rest of the world. The only individually identifiable thinkers who have achieved comparable status are the founders of the great religions in the past, and with the possible exception of Muhammad none have triumphed on a comparable scale with such rapidity. No secular thinker can be named beside him in this respect.

Marx was the greatest of all theorists of socialism.

The idea that an advanced civilization need not rest on slavery is a relatively new idea, for instance; it is a good deal younger than the Christian religion. But even if Chesterton's dictum were true, it would only be true in the sense that a statue is contained in every block of stone. Ideas may not change, but emphasis shifts constantly. It could be claimed, for example, that the most important part of Marx's theory is contained in the saying: ‘Where your treasure is, there will your heart be also.’ But before Marx developed it, what force had that saying had? Who had paid any attention to it? Who had inferred from it — what it certainly implies — that laws, religions and moral codes are all a superstructure built over existing property relations? It was Christ, according to the Gospel, who uttered the text, but it was Marx who brought it to life. And ever since he did so the motives of politicians, priests, judges, moralists and millionaires have been under the deepest suspicion — which, of course, is why they hate him so much.'

Historically, Marxism was born with the ambition of explaining everything in the world scientifically. It is known, that Marx even dealt with mathematics. Although he could not solve problems which are nowadays clear for even asinine pupils, Marx left behind for the future generations his smart tips.

One cannot do justice to Marx without recognizing his sincerity. His open-mindedness, his sense of facts, his distrust of verbiage, and especially of moralizing verbiage, made him one of the world’s most influential fighters against hypocrisy and pharisaism. He had a burning desire to help the oppressed, and was fully conscious of the need for proving himself in deeds, and not only in words. His main talents being theoretical, he devoted immense labour to forging what he believed to be scientific weapons for the fight to improve the lot of the vast majority of men. His sincerity in his search for truth and his intellectual honesty distinguish him, I believe, from many of his followers (although unfortunately he did not altogether escape the corrupting influence of an upbringing in the atmosphere of Hegelian dialectics, described by Schopenhauer as ‘destructive of all intelligence’). Marx’s interest in social science and social philosophy was fundamentally a practical interest. He saw in knowledge a means of promoting the progress of man.

The most compelling confirmation of Marx's theory of history is late capitalist society. There is a sense in which this case is becoming truer as time passes.

Marx's insight of a century-and-a-half ago was not only highly prescient, but is far truer today than in Marx's day.

The same ‘practical’ viewpoint is dominant in Marx’s conception of the cognitive functions of the mind and its role in the historical process; ‘practical’ is always regarded as implying ‘social’, and ‘social life is practical by its very essence’. So is the task of philosophy as defined in the eleventh Thesis, in what are perhaps Marx’s most-quoted words: ‘The philosophers have only interpreted the world in various ways; the point, however, is to change it.’ It would be a caricature of Marx’s thought to read this as meaning that it was not important to observe or analyse society and that only direct revolutionary action mattered. The whole context shows that it is a formula expressing in a nutshell the viewpoint of ‘practical philosophy’ as opposed to the ‘contemplative’ attitude of Hegel or Feuerbach – the viewpoint which Hess, and through him Cieszkowski, suggested to Marx and which became the philosophical nucleus of Marxism. To understand the world does not mean considering it from outside, judging it morally or explaining it scientifically; it means society understanding itself, an act in which the subject changes the object by the very fact of understanding it. (pp. 143-4)

My purpose here is to denounce an idea which seems to be dangerous and false. … Revolutionary trade unionists and orthodox communists are at one in considering everything that is purely theoretical as bourgeois. … The culture of a socialist society would be a synthesis of theory and practice; but to synthesize is not the same as to confuse together; it is only contraries that can be synthesized. … Marx’s principal glory is to have rescued the study of societies not only from Utopianism but also and at the same time from empiricism. … Humanity cannot progress by importing into theoretical study the processes of blind routine and haphazard experiment by which production has so long been dominated. … The true relation between theory and application only appears when theoretical research has been purged of all empiricism.

Precisely because Marx was convinced that the cause of the proletariat was of decisive importance for the whole future of mankind, he wanted to create for that cause not a flimsy platform of rhetorical invective or wishful thinking, but the rock-like foundation of scientific truth.

In one of his theses Marx said: 'Philosophers have so far interpreted the world. The point is to change it.' Marxism sees an innate unity between perception of the past and present practice. This unity implies continuous interaction: as time passes and history (human experience) lengthens, we draw greater lessons from it for the present; and as our present experience tells us more about the possibilities and limitations of social action, we turn to the past and obtain new comprehensions of it.

I owe most to Georges Sorel. This master of syndicalism by his rough theories of revolutionary tactics has contributed most to form the discipline, energy and power of the fascist cohorts.

The famous saying of Karl Marx in his 11th “Thesis on Feuerbach” that until today philosophy only had interpreted the world, but that from now on and further it would be about changing it, this adage could very well be modified in the following sense: Until now, the dominant philosophy only has been interpreted as philosophy of the dominators, but the moment is coming that the kenosis have to serve the dominated and have to change the world from below.