WELL, let us do this with the help of excerpts from Lenin's short essay The Three Sources and Three Component Parts of Marxism:

The philosophy of Marxism is materialism. Throughout the modern history of Europe, and especially at the end of the eighteenth century in France, which was die scene of a decisive battle against every kind of mediaeval rubbish, against feudalism in institutions and ideas, materialism has proved to be the only philosophy that is consistent, true to all the teachings of natural science and hostile to superstition, cant and so forth. …

But Marx did not stop at the materialism of the eighteenth century: he advanced philosophy. He enriched it with the acquisitions of German classical philosophy, especially of the Hegelian system, which in its turn led to the materialism of Feuerbach. The chief of these acquisitions is dialectics, i.e., the doctrine of development in its fullest and deepest form, free of one-sidedness, the doctrine of the relativity of human knowledge, which provides us with a reflection of eternally developing matter. The latest discoveries of natural science — radium, electrons, the transmutation of elements — have remarkably confirmed Marx's dialectical materialism, despite the teachings of the bourgeios philosophers with their “new” reversions to old and rotten idealism.

Deepening and developing philosophical materialism, Marx completed it, extended its knowledge of nature to the knowledge of human society. Marx's historical materialism was the greatest achievement of scientific thought. The chaos and arbitrariness that had previously reigned in the views on history and politics gave way to a strikingly integral and harmonious scientific theory, which shows how, in consequence of the growth of productive forces, out of one system of social life another and higher system develops – how capitalism, for instance, grows out of feudalism.

Just as man's knowledge reflects nature (i.e., developing matter) which exists independently of him, so man's social knowledge (i.e., his various views and doctrines — philosophical, religious, political and so forth) reflects the economic system of society. Political institutions are a super-structure on the economic foundation. We see, for example, that the various political forms of the modem European states serve to fortify the rule of the bourgeoisie over the proletariat. …

Having recognized that the economic system is the foundation on which the political superstructure is erected, Marx devoted most attention to the study of this economic system. Marx's principal work, Capital, is devoted to a study of the economic system of modem, i.e., capitalist society.

Classical political economy, before Marx, evolved in England, the most developed of the capitalist countries. Adam Smith and David Ricardo, by their investigations of the economic system, laid the foundations of the labour theory of value. Marx continued their work. He rigorously substantiated and consistently developed this theory. He showed that the value of every commodity is determined by the quantity of socially necessary labour time spent on its production.

Where the bourgeois economists saw a relation between things (the exchange of one commodity for another) Marx revealed a relation between men. The exchange of commodities expresses the tie between individual producers through the market. Money signifies that this tie is becoming closer and closer, inseparably binding the entire economic life of the individual producers into one whole. Capital signifies a further development of this tie: human labour power becomes a commodity. The wageworker sells his labour power to the owner of the land, factories and instruments of labour. The worker spends one part of the day covering the cost of maintaining himself and his family (wages), while the other part of the day the worker toils without remuneration, creating for the capitalist surplus value, the source of profit, the source of the wealth of the capitalist class.

The doctrine of surplus value is the corner stone of Marx's economic theory.

Capital, created by the labour of the worker, presses on the worker by ruining the small masters and creating an army of unemployed. In industry, the victory of large-scale production is at once apparent, but we observe the same phenomenon in agriculture as well; the superiority of large-scale capitalist agriculture increases, the employment of machinery grows, peasant economy falls into the noose of money-capital, it declines and sinks into ruin under the burden of its backward technique. In agriculture, the decline of small-scale production assumes different forms, but the decline itself is an indisputable fact.

By destroying small-scale production, capital leads to an increase in productivity of labour and to the creation of a monopoly position for the associations of big capitalists. Production itself becomes more and more social — hundreds of thousands and millions of workers become bound together in a systematic economic organisation – but the product of the collective labour is appropriated by a handful of capitalists. The anarchy of production grows, as do crises, the furious chase after markets and the insecurity of existence of the mass of the population.

While increasing the dependence of the workers on capital, the capitalist system creates the great power of combined labour. ..

Capitalism has triumphed all over the world, but this triumph is only the prelude to the triumph of labour over capital.

When feudalism was overthrown, the “free” capitalist society appeared on God's earth, it at once became apparent that this freedom meant a new system of oppression and exploitation of the toilers. Various socialist doctrines immediately began to arise as a reflection of and protest against this oppression. But early socialism was Utopian socialism. It criticised capitalist society, it condemned and damned it, it dreamed of its destruction, it indulged in fancies of a better order and endeavoured to convince the rich of the immorality of exploitation.

But Utopian socialism could not point the real way out. It could not explain the essence of wage slavery under capitalism, nor discover the laws of the latter's development, nor point to the social force which is capable of becoming the creator of a new society.

Meanwhile, the stormy revolutions which everywhere in Europe, and especially in France, accompanied the fall of feudalism, of serfdom, more and more clearly revealed the struggle of classes as the basis and the driving force of the whole development. …

The genius of Marx consists in the fact that he was able before anybody else to draw from this and consistently apply the conclusions that world history teaches. This conclusion is the doctrine of class struggle.

People always were and always will be the foolish victims of deceit and self-deceit in politics until they learn to discover the interests of some class or other behind all moral, religious, political and social phrases, declarations and promises. The supporters of reforms and improvements will always be fooled by the defenders of the old order until they realize that every old institution, however barbarous and rotten it may appear to be, is maintained by the forces of ruling classes. And there is only one way of smashing the resistance of these classes and that is to find, in the very society which sorrounds us. and to enlighten and organise for the struggle, the forces which can – and owing to their social position, must — constitute the power capable of sweeping away the old and creating the new.