p In the objective world we observe the constant interaction of phenomena, as a result of which some phenomena give rise to others; these in turn give’rise to still others, and so on. Friction, for example, causes heat, drought leads to crop failure, etc. The interaction of phenomena is also observed in social life. The national liberation movement, for example, has brought about the break-up of imperialism’s colonial system.

p A phenomenon or group of interacting phenomena which precede and give rise to another phenomenon or group are called cause. The phenomenon produced by the action of the cause is called effect.

p Cause always precedes effect, but succession in time is not an adequate sign of cause. Day, for example, follows night, but night is not the cause of day. The alternation of day and night is caused by the rotation of the Earth on its axis. Causal dependence between two phenomena exists when one of them not only precedes the other, but inevitably gives rise to it.

p Cause should not be confused with occasion. Occasion is an event which directly precedes the effect; it is not the cause itself, but sets it in motion. Thus, the legitimate assistance provided by the Soviet Union and Cuba to their natural allies—the peoples of Angola and Ethiopia—at the request of their governments for the purpose of repelling external aggression, was an occasion for a sharp intensification of aggressive actions by NATO countries on the African continent. Under the pretext of “saving” it from the “Soviet-Cuban threat" imperialism launched a crusade against independent Africa.

p The true cause of this campaign is imperialism’s desire to stop and reverse the mounting movement for national and social liberation on the African continent, re-establish full control over the immensely rich sources of mineral raw materials and fantastically cheap labour power, exploit them unscrupulously and obtain net superprofits.

Cause should also be distinguished from the conditions in which it operates. Productive labour is the cause of all social wealth. But for labour to produce wealth, an object 138 of labour and tools for working on this object are needed. Neither the object of labour nor the tools bring wealth by themselves, but they are a necessary condition for man’s labour.